Flameshot can't save the screenshot and you get this error:
~$ flameshot gui (flameshot:273151): GVFS-WARNING **: 10:59:28.441: The peer-to-peer connection failed: Timeout was reached. Falling back to the session bus. Your application is probably missing --filesystem=xdg-run/gvfsd privileges.
Kill gvfsd:
~$ killall gvfsd
Compiled with Qt 5.15.2 linux: 6.8.0-45-generic ubuntu: 22.04