My dad has had this issue ever sense he got the 3080 Ti last year. Whenever he boots into windows his screen goes black and he has to unplug and replug the hdmi cable into his Vizio 4K tv. Is there a fix to stop this? Also I’m pretty sure it happened with my 2080 ti when it was in his pc.

Since the issue is happening with two different cards I would start by using a different hdmi cable. I would then disable windows fast startup. I would then reinstall the graphics driver after removing the old driver with display driver uninstaller. I would also perform a clean boot of windows. Doing all that should resolve your issue.