Same issue; I can add a detail for my case: the exception is fired the first time the app is launched in simulator or switching between different simulator (ie iPhone 13 and 12); in both cases for the subsequent runs the MkMapView is loaded correctly.
Can I ask to all people in the thread if this exception occurs also on device? unfortunately I cannot test it on iPhone...
my configuration:
Xcode 13.2.1
monterey 12.2