Unable to edit shared family calendar events on Mac and iPhone

Since updating to Sequoia, we've lost the ability to edit our shared Family calendar in Calendar.

We have a Family account through Apple ID that my wife is the "Organizer" of and I am "Parent/Guardian".

Both of us used to be able to add events and update/edit events, but now after I've created an event, I can only "Propose" a new time. Which I've tried, but my wife doesn't get an email or notification, and neither do I, so I don't even know where that "proposal" goes.

I still can - somehow - duplicate, delete, and create events... but I can't change the time or make notes or anything along those lines. I have no idea how I have the power to delete & create but not edit?!?!

Any help here would be amazing.

[Re-Titled by Moderator]