Wow, I’m running the same setup: debian, sway, fuzzel, foot, RX 6600. Unfortunately, I have no good advice as I have not run into that issue. All I can say is that I never specifically installed the amd drivers, amdgpu was already installed. Do you also have gnome installed with the default debian install? Does it do the same thing in gnome?

If you haven’t played in a bit, the old wiki kinda died, but this exists, if you aren’t already familiar:

Hitchhiker’s Guide to the Cataclysm

which is incredibly useful for crafting and figuring out where to search for specific things.