# Stuck with what's happening with MQTT topics

**URL:** <https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714>\
**Category:** General\
**Created:** [19 November 2025 03:07 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714 "2025-11-19T03:07:51Z")\
**Posts on this page:** 14\
**Page:** 1

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**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [19 November 2025 03:07 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/1 "2025-11-19T03:07:52Z")

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Folks, I'm stuck.

# The story:

I have MQTT and use it to move messages between machines.

One of which is my Public\_IP address.

Yet, if I run `MQTT Explorer` it says that topic is empty.

Strange as it is published to that topic.

See piccies.  
(Follow red line for how it gets published.)

 ![Screenshot from 2025-11-19 13-48-40](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/3/c3d4d60d947601fffa2a3763fa46cbdf935edb2b.png)

You can see the value it it goes to an `MQTT` out node.

The node's config:

 ![Screenshot from 2025-11-19 14-02-28](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/d/0/d0b013390efea732e8ae9a5cc832390d1d1d7626.png)

MQTT Explorer's take on things.

 ![Screenshot from 2025-11-19 13-49-26](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/5/c5126148feac5bfb2d2d896491e62dae3f85fbec.png)

See how it is _EMPTY_.

I test it from a CLI and it doesn't get set there either.

 ![Screenshot from 2025-11-19 13-52-59](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/e/ce335c37a2dea7f90f0967c6456be921c9706f6b.png)

Where's the elephant I'm not seeing?  
🤷

Just to make sure I'm not going nuts, I tested it with a whole new topic.

 ![Screenshot from 2025-11-19 14-15-20](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/a/8/a8634c6d0f97f699f784e9d45965d4fe79f11d35.png)

I also checked ALL my machines.  
NO ONE ELSE is broadcasting on that `topic`.  
ONLY THAT ONE MACHINE AND ONLY IN THAT ONE PLACE.

# UPDATE:

Even more weird.

I set the IP address to `1.1.1.1` - just for the fun of it.  
It is acknowledged in the `MQTT in` node.

 ![Screenshot from 2025-11-19 14-21-09](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/8/186f82c684ed493381cef4d28d124713dd168fb0.png)

And you can see the IP address in MQTT Explorer

 ![Screenshot from 2025-11-19 14-22-53](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/4/d/4d82ea2f00e6d5ac87b2fa3291cbb91165d100ab.png)

But if I set it back to what it REALLY is - partly hidden but anyway.....

You can sort of see the real IP address. Anyway, I enter it and broadcast it from the CLI.  
You can see how it is sent/received by the `MQTT in` node - as before.

But MQTT Explorer goes back to showing only `{}`

 ![Screenshot from 2025-11-19 14-23-19](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/2/c205e4e4cd4fbc997f570490f375768db98d6404.png)

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<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [19 November 2025 03:47 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/2 "2025-11-19T03:47:58Z")

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Ah, seems I am running an OLD (discontinued) version.

Can't find an update at the SNAP site.

😢

Sorry folks.

(If you can help me get a newer one.)  
Ubuntu 22.04 LTS

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [19 November 2025 08:58 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/3 "2025-11-19T08:58:57Z")

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> [@Trying\_to\_learn](#):
>
> I am running an OLD (discontinued) version.

Of what ?

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [19 November 2025 09:02 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/4 "2025-11-19T09:02:25Z")

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If you mean mqttExplorer then I am running the snap version latest/stable 0.4.0-beta4 on Ubuntu 24.04 and I have seen no issues.

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [19 November 2025 14:43 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/5 "2025-11-19T14:43:52Z")

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> [@Colin](#):
>
> 0.4.0-beta4

I believe that IS the latest. Thomas long ago moved on from the project I believe and it is no longer being developed.

One day I may have the time to complete my Node-RED version of something similar!

* * *

Scrub that, there is a "beta6" version. But it only lists a single change of little seeming consequence.

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [19 November 2025 16:25 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/6 "2025-11-19T16:25:29Z")

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> [@TotallyInformation](#):
>
> there is a "beta6" version.

That is also available as a snap, in the latest/beta channel.

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [19 November 2025 16:44 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/7 "2025-11-19T16:44:40Z")

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> [@TotallyInformation](#):
>
> One day I may have the time to complete my Node-RED version of something similar!

Yes please!

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<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [19 November 2025 18:36 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/8 "2025-11-19T18:36:21Z")

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Could you elaborate on how I get it?

If/when I go to SNAP all I see is the existing version I have listed.

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<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [19 November 2025 18:58 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/9 "2025-11-19T18:58:36Z")

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> [@Colin](#):
>
> If you mean mqttExplorer then I am running the snap version latest/stable 0.4.0-beta4 on Ubuntu 24.04 and I have seen no issues

Indulge me then.

Get your public IP address and broadcast it to a topic. (Say `Public_IP`) and look at what MQTT Explorer says is in the channel.

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [19 November 2025 19:45 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/10 "2025-11-19T19:45:35Z")

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> [@Colin](#):
>
> Yes please!

Yes, well, rather a lot going on just now and I'm afraid this has dropped down the priority list somewhat. I see how inspired I feel. 🙂

Right now, I've FINALLY gotten round to trying to document setting up Cloudflare Zero Trust to use with Node-RED and UIBUILDER. Long overdue.

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<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [19 November 2025 21:54 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/11 "2025-11-19T21:54:14Z")

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It isn't to do with one's IP it is only specific IPs that give the problem. When one publishes "58.169.129.172" to a topic (any topic) mqttexplorer shows `{}`. I think a clue is that if you click on the value and look in the right hand side it says Decoded SparkplugB

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/5/c/5c868fc1fa81f54cef82882144214f006e3c294a.png)

See [MQTT-Explorer 0.4.0-beta4 SparkplugB decode some strings as "{}" · Issue #792 · thomasnordquist/MQTT-Explorer · GitHub](https://github.com/thomasnordquist/MQTT-Explorer/issues/792)

It is fixed in the edge version which you can get by running  
`sudo snap refresh --edge mqtt-explorer`

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<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [20 November 2025 03:54 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/12 "2025-11-20T03:54:27Z")

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Thanks.

Did command and that _Fixed_ it.

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<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [21 November 2025 16:52 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/13 "2025-11-21T16:52:46Z")

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> [@TotallyInformation](#):
>
> Yes, well, rather a lot going on just now and I'm afraid this has dropped down the priority list somewhat. I see how inspired I feel.

And inspired I was on a quiet Friday afternoon!

> [@Node-RED version of MQTT Explorer](https://discourse.nodered.org/t/node-red-version-of-mqtt-explorer/99738):
>
> Hi all, In a recent thread, I promised @Trying_to_learn that [I would revisit a project I started](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/11) quite a long time ago now, which is a replacement for the [MQTT Explorer](https://mqtt-explorer.com) desktop app. So here is my first draft. It is still very basic but it demonstrates the principles. If you have anything you particularly want to see, let me know. Not promising anything but I will certainly add to the backlog. The idea here is to have a useful, purely web-based view into an MQTT environment. But also to showcas…

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [5 December 2025 16:52 UTC](https://discourse.nodered.org/t/stuck-with-whats-happening-with-mqtt-topics/99714/14 "2025-12-05T16:52:52Z")

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