Flickering on Linux while in fullscreen

[K1NGM4RV]

I recently switched to linux (Ubuntu based distro) and encountered a problem using Anki: the screen flickers if I switch my keyboards (super + space) while using this plugin

I'm working with Wanikani for Anki and I need to type in Roman but also in Japanese letters. Switching between these inputs works really well (since I've installed ibus-Anthy) but the screen flickers as soon as I do so. Now I'm using the "no distraction addon" (and the latest version of Anki 2.1.39) and the screen shows the desktop for a millisecond as soon as you switch the keyboards (Roman -> Japanese & Japanese -> Roman). This issue only happens in Anki (other programs work fine). It doesn't matter if I use ibus or fcitx.

Any help is very much appreciated, thank you very much!
Best regards
Marvin

Edit: the behaviour is definitly because of this plugin unfortunately. Anki works completely normal without it.