Booking Appointment Graph API Update No Longer Updates Service Name

The service name property of an appointment was previously editable per docs and testing.
https://learn.microsoft.com/en-us/graph/api/bookingappointment-update?view=graph-rest-1.0

Now when an update occurs via API, the service name completely resets to the default service name of the appointments service ID. You can still pass the service name when creating and appointment via the API, but any updates will break it. Anyone else experiencing this issue?