Wifi/Ethenet problem.

Hi All, my first time on this forum, please be gentle
The other day my almost new, custom built windows 11 PC (not built by me) failed to connect to our home wifi, I had facility to use Ethenet from our tried and tested powerline adapter so tried that still nothing. The WiFi networks showed available networks, I could connect but got no Internet access and the Ethenet wasnt connecting to anything .
I had noticed the day before that I kept getting disconnected from our Virgin media wifi but just thought it was a little patchy as it is occasionally. Then nothing, zip, nada, zero Internet but I could still see the available wifi networks but nothing at all from the Ethenet, unsual as it's normally a good connection.
Worth mentioning my other devices are connecting to the wifi network without any issues.
I panicked as I had to finish some work, so I ordered a usb WiFi adapter thing a twin antenna usb 3 one. I installed it and I had a great wifi connection but sadly no Internet connection.
I have tried everything following online help pages
Could it be my pcie wifi card gone bad? But if so what's up with the Ethenet
Sometimes my standard wifi card connects but still nothing. I can't roll back to any earlier os point as its greyed out and I don't really want to re-set the whole system and have to start again.
Please can someone help?