I have filed as FB13205932, would recommend others also file a Feedback and share their ticket numbers in this thread.

How long should we expect to wait for approval? I submitted a request last week and am still waiting to hear back.

So! Asked around and was pointed to the NSSupportsAutomaticTermination key in Info.plist. From the docs: Automatic termination allows an app that is running to be terminated automatically by the system when certain conditions apply. Primarily, the app can be terminated when it is hidden or does not have any visible windows and is not currently being used. Exactly what I was seeing! Setting this to false fixed the issue. (Thanks to J**** and J**** for the help!)