Next steps for diagnosing the problem?

I’m at a bit of a loss on where to start troubleshooting this.

Last Tuesday, out of seemingly nowhere, 3/4 ports on my GPU stopped registering signals to monitors, only a HDMI port worked. However, games and everything else seemed to have no issues.

Wednesday, now the GPU seems to be almost completely isolated from the computer’s operation. Wallpaper engine and simple games now max out CPU usage. Another game also doesn’t identify the PC has a GPU capable of running it (Deep Rock Galactic Rogue Core). Monitor is still displaying signal from the GPU port.

PC Specs: AMD Ryzen 9 5900X

Gigabyte Radeon 7800XT

TUF Gaming B450 Plus-II

48GB RAM (unsure of brand)

Windows 10

Current troubleshooting:

1. PC restart (nothing)
2. DDU uninstall drivers and reinstall (nothing)
3. Update display drivers and any other “urgent” windows updates (nothing)

Does anyone have any ideas to troubleshoot? My next option would be to pull the GPU and check the warranty (ordered May 2024) so I can send it in for repairs.