Can't click on System Preferences or file dialogs?

[xienze]

This one has been driving me nuts and I can't seem to figure out what to Google for. I'm on the latest macOS and maybe a week or two ago, out of the blue, whenever a file dialog (not Finder, that works just fine. I'm talking about an app's typical "open file" dialog) opens I can't click on anything. I can tab between the search text field and the favorites list. That's it. I can't tab into the file selector part of the dialog and I can't click on anything but the search text field. Also I'm having a similar problem with System Preferences. I can click on the initial page with all the icons, but once I'm on a specific settings page I can't click on a damn thing. Does anyone know WTF is going on?