Solus Plasma - Unstable repository, fully up to date:
Firefox on launch complains it is not the default browser even tho IT IS the default. No matter how many times you click "make default" it does nothing.
GTK_USE_PORTAL=1 which was just enabled seems to be causing the issue.
Comment out the line, reboot, problem goes away.
can you go under firefox settings and check if you have ask always reg default browser? normally you set firefox as default via the plasma settings
Yep "Always check if Firefox is your default browser" is enabled. Pretty sure "always check" is enabled by default. I knew I could make it stop asking me. I just thought you might like to know the issue exists. :)