Microsoft Bookings does not show correct date for all-day appointment

I set up a service with only pre-defined appointment slots, and I created an appointment that spanned three days, starting on a Tuesday. However, when I tested what it would be like for a user to register, the appointment slot showed up as starting on the day before (i.e. Monday).

Moreover, when I registered for the "Monday" appointment, it actually created a new appointment starting on that Monday. That new appointment, in turn, showed up as starting on the day before (i.e. Sunday).

As it is, this renders the app almost completely non-functional for my purposes, and I am extremely disappointed.