One of our devices now has this exact issue. Can get to the property overview under Caldendars, but tapping either property (we have 2) then just produces the infinite-loading bug.
I have deleted the App and reinstalled it twice (and restarted the iPhone of course), but no luck. Strangely, deleting the App did NOT remove my login credentials, which normally happens when you delete and reinstall an iOS app. So my guess is that deleting the AirBnB app does not clear some critical data cache somewhere and that this cache is the source of the problem.
Hopefully they can get this fixed, as my cleaners rely on their App to know when they need to clean, so this is a pretty critical bug.