No response from editor but dashboard UI stills works ?! (FIXED)

[vtgav]

I have node-red V2.2.0 installed on an Azure debian 10 VM accessing a local MySQL database, using latest Chrome to access the editor and dashboard ui.
Its been working fine for days as I've been developing the application. Today I had some sort of strange blip and when I refreshed the editor I just got a blank screen, however the dashboard UI still works.

I've stopped and restarted node-red - same result; blank node-red but dashboard UI works.
I've stopped and restarted the VM itself, same results.

checking the node-red log file gives something interesting

4 Feb 12:25:13 - [info] Started flows
4 Feb 12:25:13 - [error] [mysql:90954e215c0fcf35] Database not connected
4 Feb 12:25:13 - [error] [mysql:1443a7ab59b87dc9] Database not connected

but . . . what does it mean ?? the dashboard UI works fine, and access data from mysql ?? and in any case I can't see the flows in order to change anything. But maybe the mysql error is not relevant to the real problem here.

If I use the chrome tools to look at that page there is an error message on there that may or may not be relevant :-

*Access to CSS stylesheet at 'http://obfuscated:1880/vendor/jquery/css/base/jquery-ui.min.css?v=2.2.0' from origin 'http://obfuscated:1880' has been blocked by CORS policy: The request client is not a secure context and the resource is in more-private address space private.*

as an aside, the VM also runs a docker container with node-red which accesses the same mysql database - this also works fine from a dashboard UI perspective, but the editor behavior is different - it does load and does show its flows but loses connection within a few seconds and can't remake it. If I refrech the browser same thing happens - initial load then loses connection.
This docker container isn't causing the main node-red problem - I've restarted the VM without the container running and get the same behaviour on the main editor screen - ie: blank

I'm a bit lost really
any ideas appreciated . . .
Gav

[vtgav]

OK chasing down the chrome error message helped . . .

see Chrome CORS error on request to localhost dev server from remote site - Stack Overflow

changing my chrome setting for :
chrome://flags/#block-insecure-private-network-requests

made the editor reappear ( no idea why it suddenly affected me from this morning ), however, I now get the 'lost connection to server' problem

[vtgav]

checking the chrome console after the CORS flag fix gives me this every time I get the lost connection message

WebSocket connection to 'ws://obfuscated:1880/comms' failed: 
s @ red.min.js?v=2.2.0:16
(anonymous) @ red.min.js?v=2.2.0:16

[vtgav]

OK an update with some 'egg on face' I fear . . . I do need to set up DNS and certs and use https of course, but the real cause of this I've realised was that the 'strange blip' was after I connected to our company VPN and hence was accessing Azure via a different route apologies for being a complete idiot.