It is very frustrating that the only way to resolve this solution seems to be go into Google software to make a bridge or disable the new features in this deployed software to make an already functioning feature work again.
While disabling the new shared calendar settings does seem to work to get the Calendar loaded it doesn't fully solve the problem as:
1 - new features are lost as a result
2 - in this "solution" the calendar is still an external calendar to the user's primary calendar and cannot be integrated into the primary calendar - this prevents further sharing and distribution throughout the team and seems to prevent an integrated division travel calendar which is what we had before.
Overall this is bad policy, bad software testing and rollout, bad response and bad workaround.