Earlier quoted context omitted.
IDK. Sway is my daily driver. I just checked Firefox, and the screenshot tool works as expected (including clipboard). So unless GP is talking about capturing non-Firefox windows with that tool, I do not have that issue. This Firefox instance is running on native Wayland. The only issue I have with it is sometimes the coordinates for the context menu are wrong. But yeah, there might be compat issues, if some protocol…
I may have done something wrong. I am not highly knowledgable here. For example, I just learned of Pipewire. That said, the problem occurred for me when using the NixOS package firefox-wayland. It is possibly better to use upstream firefox with Wayland, but I have not tried; I am just running firefox on Xwayland for now.
MOZ_WEBRENDER=1 MOZ_USE_XINPUT2=1 GDK_BACKEND=wayland