2 years of bugged screenshotting in Mint / Cinnamon
Open source tends to get into these sorts of situations...
https://forums.linuxmint.com/viewtopic.php?t=202909
https://github.com/linuxmint/Cinnamon/issues/3981
https://bugs.launchpad.net/linuxmint/+bug/1620318
The workaround is to do this:
Command:
sh -c 'sleep 0.1; gnome-screenshot -a'
I think what it does is force the computer to wait 0.1 second, and then activates the usual command. No idea why this works.
man pages: