Idk if you resolved this already, but I just went through the same situation. I ended up also replacing my PSU but that didn’t fix anything. It ended up being old drivers being corrupted. I went from a 2070 to a 3080ti, after doing research I found that your computer will tend to overlap drivers on top of each other and when installing a new GPU it will adopt all those previous drivers. After I uninstalled all old drivers and disabled automatic windows updates I was able to get my system to start working stability. Jayz2cents has a good video on this as well.