Slider issue on Android Chrome browser

I have started to notice that when using a slider (sending value when released) if I touch and move the slider knob the value won't be sent. However, if I press the the slider bar instead which moves the knob it'll send the value fine.

Funny enough this only occurs on Android Chrome, Windows Chrome works as expected (changing the value to send when changed instead of on release also works fine).

Confirming the same issue on various Android devices and all tested browsers: Android 7, 8, and 9 in Firefox, Chrome, and Fennec.

Anybody knows why the sliders don't work?

Can you post the startup log you see when starting node-red in a terminal. Then we can see the versions of everything you are using. What hardware and OS are you running node-red on?

There you go, node-red runs on an updated local Devuan-Linux server with Intel(R) Core(TM) i5-3320M and 8GB Ram as user homeaut:

homeaut@router:~$ node-red
23 Jul 14:52:11 - [info] 

Welcome to Node-RED
===================

23 Jul 14:52:11 - [info] Node-RED version: v0.20.7
23 Jul 14:52:11 - [info] Node.js  version: v10.16.0
23 Jul 14:52:11 - [info] Linux 4.19.0-0.bpo.5-amd64 x64 LE
23 Jul 14:52:11 - [info] Loading palette nodes
23 Jul 14:52:12 - [info] node-red-contrib-milight-2@1.0.8 started
23 Jul 14:52:12 - [info] Dashboard version 2.15.5 started at /ui
23 Jul 14:52:12 - [info] Settings file  : /home/homeaut/.node-red/settings.js
23 Jul 14:52:12 - [info] Context store  : 'default' [module=memory]
23 Jul 14:52:12 - [info] User directory : /home/homeaut/.node-red
23 Jul 14:52:12 - [warn] Projects disabled : editorTheme.projects.enabled=false
23 Jul 14:52:12 - [info] Flows file     : /home/homeaut/.node-red/flows_router.json
23 Jul 14:52:12 - [info] Server now running at http://127.0.0.1:1880/
23 Jul 14:52:12 - [warn] 

---------------------------------------------------------------------
Your flow credentials file is encrypted using a system-generated key.

If the system-generated key is lost for any reason, your credentials
file will not be recoverable, you will have to delete it and re-enter
your credentials.

You should set your own key using the 'credentialSecret' option in
your settings file. Node-RED will then re-encrypt your credentials
file using your chosen key the next time you deploy a change.
---------------------------------------------------------------------

23 Jul 14:52:12 - [info] Starting flows
23 Jul 14:52:12 - [info] Milight:milight1:undefined
23 Jul 14:52:12 - [info] Started flows

node-red was installed this way:

bash <(curl -sL https://raw.githubusercontent.com/node-red/raspbian-deb-package/master/resources/update-nodejs-and-nodered)

I am seeing the same symptom as you, when running Chrome on Android the slider does not send its value on release (or at all when sliding). It works ok with Chrome and Firefox on Ubuntu, but Waterfox (56.2.12) has a different problem in that it sends the value as it slides instead of at the end. This is with dashboard 2.15.5 and node red 0.20.5 running on Ubuntu 19.04. nodejs version 10.16.0.

Just to add to this because I think it's related:

Also the buttons of the dashbaord don't work in Android browsers. They stay selected even after releasing them causing double touches when browser gets refreshed. This turns node-red's gui for Android quite useless.

Anybody can confirm that here and maybe we need ot report the problem somewhere else to be noticed.

Is github the better address for bug reports?

I dug a little bit deeper. It seems that android somwhow doesn't sent a release event when using touch.
I connected a mouse to the android tablet I use for testing and using the buttons on the mouse both problems are gone.

I also do recall a setup for raspberry pi with a touchscreen and I think it also keeps the buttons selected (which didn't matter much in that setup I made)..

So I assume that touchscreen in dashboard is basically broken?

Can apple and other PC touch screen users confirm this?

NoGRo's solution at Momentary button on Dashboard seems to allow defining a button that DOES work correctly on touch screens - I assume this way we could also build a working slider.

Somewhere seems to still be a mess-up with click and touch events in the dashboard code.

I opened an issue on github: https://github.com/node-red/node-red-dashboard/issues/523

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