Solved Confirm LAN connection.

[isladogs]

This is a screenshot from my laptop showing both Ethernet & Wifi connected:

Interestingly, the Network Status screen showed the connection changing from Ethernet to WiFi & back again over a period of a few seconds.
That's despite me having recently purchased a high spec Mesh WiFi system which is about as reliable as you can get
That seems to reinforce the point about how easily WiFi connections can get broken, even if only briefly

For info, the laptop is running Win 10 v20H2 Home (NOT Pro) which seems to quash another theory

 

[The_Doc_Man]

After some research, it appears that it is related to a VLan setting. A corporate system with a Group Policy downloaded at system connection time might very will override the offending setting,

Enable simultaneous network connections (Wifi & Ethernet)

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