Sudden Problematic Transparent Background

The issue happens with Aegisub. It has also happened to me when I used Ubuntu with its default editor.

The issue is that Aegisub is using a transparent background now, and this transparent background will overlap with the foreground.

This issue didn’t happen yesterday, which is weird. I have installed a few softwares after that.

Screenshot:
Imgur

The overlap:
Imgur

Does anyone know how to solve this/why this happens?
I’ve been looking for solutions, but all I get is “how to make x transparent.”

Desktop is Cinnamon and theme is Dracula. I’ve tried using another theme but it doesn’t work.

Solved. GTK_IM_MODULE=hime was causing the issue