Deleted the original message. I have a different context of the issue.
Darktide reliably causes this issue, but it is intermittent. If Discord is on it occurs more often.
Internet stops working on the main ethernet interface. The interface itself is still showing as online, but no network connections can be made. Even internal.
Journalctl does not show anything specific happening when the internet goes down.
My motherboard has a WiFi interface, so I tested it. It works without any issues.
Also, I do have a TP-Link ethernet card in this computer. So the interface is not the motherboard's.