Supervised family member cannot view "Family" calendar tried all workarounds

I set up google Family in Family Link a while ago. I have 2 supervised family members (teenagers). Both parents can view "Family" calendar but the 2 teenagers cannot view "Family" calendar on their devices via native iPhone calendar app or Google Calendar app. 

I tried all the workarounds noted in the threads below:

1) Tried adding a new family member in Family Link to see if that would trigger a re-sync

2) Tried adding Family Calendar ID to teenager calendars and subscribing resulted in "you do not have access to this calendar"

3) Tried adding Family Calendar Public URL to teeenager calendars and subscribing "you do not have access to this calendar"

I have a TON of events on this family calendar we've used it for years and it will be really hard to move all events to a new shared (non-family) calendar. Is there any other workaround that might get Family calendar working? 

Thank you!