2 streaming PCs on same power strip both lost ethernet connection

Hello, I'd like to preface this by saying that I am posting this on behalf of a friend who doesn't use Reddit.

My friend is a streamer and streams using 2 PCs, from what I understand. I went ahead and copy-pasted what she sent me, a long with a few *additions of my own to add details that might be important and clear things up:

Problem: Both of my PCs on the same power strip have lost ethernet connection. Partner's computer on a different power strip is completely fine. (*Her and her partner sit back to back in the same room) So on Monday, I built a second PC to run my streams off of. Everything went great on stream and there was NO issues tech wise. Both computers were running fine the entire night (about 3-4 hours). They are on the same power strip, but it's rated correctly for handling two PCs. After ending the stream on Monday, I turned the computers off and went to bed.

The next day I was plugging in a small mini monitor into the second PC and the USB-C port wasn't strong enough, so it was putting out an error stating that there was overcurrent detected on a USB device and the computer would be turned off. I had to turn it on again about twice because I was trying to figure out what it was (because I had gotten a smaller keyboard as well that I had plugged in at the same time) and eventually found out it was the USB-C port. Ran the monitor through a USB-C to USB adapter and it's working fine.

I do NOT know if both PCs had issues at this point. I really wish I had noticed before then if it did. But after that we (*her and her partner) noticed that both of my PCs were not detecting their ethernet cables. At all. We completely disconnected the second PC from power for a bit which did bring it back on ethernet until today (*Tuesday), but it was at a fraction of the speeds it should have been. Main PC's ethernet seems completely dead. When testing the main PC's ethernet cable on a laptop, it wouldn't detect at all. Second PC's did detect but with the slower speeds. I have new ethernet cables coming in as well as ethernet adapters.

But I suppose my main question is this:

What would cause BOTH ethernet cables (*and/or both ports) to just... stop working? I don't think it was a short, but at this point I have no idea what to do or what caused this problem to begin with.

The PCs are next to each other physically, and as stated before are connected to the same power strip which is rated correctly for two computers.

Neither computer is overclocked.

Also looking for advice on how to fix, but I'm figuring at this point only new cords will work.

Thanks in advance for any and all advice given!