PySide2 app doesn't capture keyboard input

[Kettle3D]

Hello, I'm creating a simple Qt app for the first time, a lock screen that prompts me for a password. But for some reason it won't let me type anything in.

I have a QLineEdit widget for entering the password, but when I try to type anything in it gets sent to the terminal, not the app, which is focused, full-screened and not decorated by the window manager.

There is a temporary button at the bottom of the screen so that I can hide the lock screen without typing in my password because I can't, and pressing that button works fine.

Does anyone know what might be going on here?

Update:

Clicking on the text box also doesn't show any indication of focus.

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Ubuntu 20.10 (groovy gorilla), X11, Marco Window Manager (Adaptive compositor), Linux 5.8.0-34-generic #37-Ubuntu SMP Thu Dec 10 18:01:14 UTC 2020 amd64

[Kettle3D]

OK, I found out that the issue has something to do with me using setWindowFlags(Qt.X11BypassWindowManagerHint).

Does anyone have ideas as to what else to use? (Ideally I don't want an 'X' button on my lock screen, or be able to press Alt+F4 to close it)