imported calendar overwrites over information

[Joanna550]

Hi

I maintain our "master" calendar on Airbnb and it's always synced without problems to several other listings.  I recently added a new sync and now find that this new sync is overwriting everything on Airbnb (except Airbnb bookings).  Logically what's happening is that when they sync information from my calendar to their calendar it takes my existing bookings & calendar blocks to their calendar; but as soon as it syncs back it now shows the same dates as blocked in the name of their calendar and it's overwritten my own information that I added (except private notes).  It doesn't create a problem in terms of double bookings but I've lost the immediate sight of who has which dates blocked.

Any suggestions for how to stop the imported information showing in my calendar?

Thanks

Alan