Same issue here. AppleScript still can not retrieve track info on macOS 11.3 Beta in stream mode.

I can confirm that this issue has been fixed in today's release of macOS Big Sur 11.3 beta 2.

@f_anton You can try to delete the WeeklyPlanViewModelTests.swift from your tests target by "Remove Reference", and add back again, It should work. At least in my case.

I've also meet this issue several times, app stuck at calling AEDeterminePermissionToAutomateTarget, only restarting system works. I've reported as FB9030678.