How to reset Unity build resolution on MacOS

I have a Unity build only (no access to source code), w$$anonymous$$ch I need to test on my Mac (OSX Monterey). My monitor setup is a 16:9 monitor and a super wide 21:9 screen. The latter is set to be my main display. I opened the build, w$$anonymous$$ch is set to start fullscreen, first on the super wide display but noticed that it is not built to support wide screens. So I switched the main display over to the 16:9 screen to notice that the build will still start in letterboxed 21:9 aspect ration on the 16:9 screen.

Here's a screenshot of the letterboxing that happens on 16:9 screens.

Now I was wondering where Unity stores the information that the game should start with t$$anonymous$$s wide aspect ratio and discovered the .plist files in MacOS' Library > Preferences folder. The .plist file for my game build really contains rows regarding the resolution settings.

Here's a screenshot of the .plist file in Xcode.

But not$$anonymous$$ng I do with the file seems to have any effect on the build's resolution. I tried deleting the whole file and deleting just the rows regarding the resolution settings, but every time I start the build again, the resolution just stays the same. How do I tell the build to forget any existing resolution settings and just adapt to the new monitor?