Today my Guake Terminal started acting up in a way I haven't seen before - every time I press AltGr (which on my Swedish keyboard is the right Alt, right next to Spacebar on the right-hand side) the terminal looses focus and hides. On my Swedish keyboard this is extremely inconvenient, since AltGr is used to type pipes (|)...

I did install some updates which required a restart of my system today, but IIRC that was only Ubuntu Base and nothing else. I don't know for certain if this behavior was present before the update - since the popup came up when I started my system, I didn't do much work before I installed them and rebooted.

I also took a look in the Guake preferences to see if there was anything fishy with the keyboard shortcuts, but AltGr isn't used at all, and all other shortcuts work as expected. AltGr works normally in other context, such as an actual Terminal window (opened e.g. by pressing Ctrl+Alt+T) or typing here in Chromium.

What could have caused this? How do i troubleshoot and/or fix it?