I went from a 3070 to the 6800 XT, all games are unplayable in full screen or borderless mode, heavy stutter or flickering. When in windowed mode, games are all butter smooth. I've tried all the possible solutions, even went from manually disabling and re-enabling all the radeon software settings indivually to a full on windows reset with clean drivers. I tried different monitors, freesync on and off, no avail. Again, games are all butter smooth in windowed mode.
I've also done a lot of research on this, with some users claiming my same situation, with no solutions to date.