If #Joplin stopped working for you after the last Linux Mint Cinnamon 21.2 update then this helpful tip might work for you from Joplin's discourse|

"A workaround is to install jopin with the appimage install script rather than flatpak"

wget -O - https://raw.githubusercontent.com/laurent22/joplin/dev/Joplin_install_and_update.sh | bash