Came in this morning and found that it’s broken again.
It looks like it’s to do with the way it’s invoked - the application icon in my K-menu runs /snap/bin/firefox %u and KeepassXC doesn’t work.
Until this morning, I’d been running with snap run firefox. Using that again, KeepassXC springs back into life
snap list only shows one Firefox install.
Edit: editing the K-menu application to run snap run firefox doesn’t fix it. It only seems to run when snap run firefox is invoked from a terminal. Editing the application shortcut and setting “run in terminal” gets it working - I guess there must be something different in the environment…