Microsoft Bookings Has to Toggle Months Before Showing Available

Hi,

It looks like there is a bug in my Bookings calendar for all-day events. When I first load the page, it (incorrectly) shows as no days available (see below):

However, when I toggle to February, then back to January, it now (correctly) shows some Mondays as available:

Sometimes reloading the i-frame fixes it, sometimes not. What's going on here? I'd like to get this fixed for my clients.

Thanks,

Julia