Any popup open in a reduced square box and can't click or see anything.

I use the ppa for keepass2 (https://launchpad.net/~jtaylor/+archive/ubuntu/keepass)

The version I have is the latest of the repo. I can't see the version number because this popup open in a reduced square state like the others.

I assume the version I have is v2.47 (current latest stable release)

I've tried to reboot my computer and launch keepass2 again, not working.

I don't know what I need to provide on top of these information, but feel free to ask.

To reproduce the bug on Ubuntu 20.04.2 LTS, do:
* Launch Keepass2
* open your database
* Do any action supposed to open a popup like "Edit Entry..." or "Help>About KeePass"
* The popup appear in a small square (cf attached print screen to show it)

The annoying thing about this bug is that I can't resize the popup to make it bigger. Thus, any action/information that happen in a popup is unusable. I can't see the keepass version, edit or see any entry. I can only copy login and password because this doesn't require a popup.

When I launch Keepass2 in command line, the only information I got is this error message at the start, and no additionnal error message when a failed popup appear:
> Gtk-Message: 09:51:27.606: Failed to load module "canberra-gtk-module"

I've then installed additionnal packages:
> sudo apt install libcanberra-gtk-module libcanberra-gtk3-module

to no avail, no the error i get is:
> Could not set X locale modifiers
but the popup bug is still here.