Mistake on my part here. I was catching the error and not printing it. The sporadic working in the simulator was a red herring. The error was that my AASA file was missing the appropriate values, but it wasn’t. What eventually solved it was cleaning my build folder AND deleting the copy installed by TestFlight from macOS. Worked great on the next build.

One more thing to note is that this is native macOS, not Catalyst.