Very weird window decorations

Afaiu you are using custom window decorations. This has some weird effects, atleast when using `sway`.
For example the (native) file chooser is missing its "normal" decoration and instead has a weird bar on top (marked in red by me in the screenshot).

Furthermore the main window is missing borders, which both the file chooser and the a "normal" window (the terminal visible) have. This makes the main window look very strange when placed above another window with the same background color.


Finally instead of the normal border, the file chooser usually renders a drop shadow instead: