GS605v5 - my wi-fi is working, but my computer's ethernet connection hasn't worked for days

My ISP is Spectrum.  My modem (and their tests) indicate that I'm getting service.

I have a Netgear switch that relays things to my Wi-Fi mesh system and to my PC.  I've never had trouble with it before.  But a few nights ago, the ethernet connection on my computer stopped working (so I had to switch to Wi-Fi, which is still working).  Since then I've contacted Spectrum, tried a few random tricks I found online to try to reset or diagnose the problem, etc...to no avail.

The light for my Wi-Fi port is blinking green.  The light for my ethernet cable (running to the PC) is solid green.

On my computer, it says "Unidentified Network - No Internet" for my ethernet connection.

Any help/advice would be greatly appreciated.  Be forewarned - my "expertise" on these matters is completely non-existent.  So the simpler you can keep the explanations, the better it will help me!  Thanks so much.