Can't launch firejailed programs from inside plasma

Since putting most of my programs into a firejail wrapper, plasma/krunner doesn’t show them anymore and it isn’t possible to have them launch on startup the normal/plasma way.

Interestingly, not all programs behave the same:

thunderbird is also not visible in krunner but can still be launched from its original “Pin to taskbar” shortcut in the taskbar.

freetube can be launched from a newly created “Pin to taskbar” shortcut but when opened this way, it opens an empty electron container, not freetube itself.

telegram-desktop cannot be launched from the taskbar at all, neither by a “Pin to taskbar” shortcut nor by a manually generated .desktop file with telegram-desktop as the command.

However, launching these program from the terminal works fine.

What is the reason for this? Is there a way to overcome this?