Yes, this is a huge frustration for me with Fibery’s calendar view and its Google Calendar integration. It basically means I end up not bothering with the combined calendar view, which makes it mostly useless in practice to integrate with Google Calendar.
I think this may be more of a feature request than a “bug”, per se. But either way I’m voting for/in support of addressing it!
I want to add that syncing Google Calendar also affects Timeline view: you can no longer add a new Fibery entity by clicking/dragging on a day/time in the timeline after adding Google Cal or any other event type with read-only dates. Not ideal.