When you mark time as "time off" in MS Bookings, it should block out those timeslots and prevent customers from booking appointments during those times. If you're finding that customers are still able to book appointments during your "time off" slots, there are a few things you can check:
Double-check that the "time off" slots are set up correctly: When you add "time off" in MS Bookings, you should be able to specify the start and end times for the time off period. Double-check that you've set these up correctly and that the time off slots are actually blocking out the times you're unavailable.
Check your booking policy settings: MS Bookings has a variety of policy settings that control how appointments can be booked. For example, you can set minimum and maximum notice periods for bookings, as well as how far in advance appointments can be booked. Make sure that your policy settings are set up correctly and aren't allowing bookings during your "time off" slots.
Ensure that you have the correct time zone set: If you're finding that appointments are being booked during your "time off" slots, it's possible that the time zone settings in MS Bookings are incorrect. Double-check that you have the correct time zone set up in MS Bookings and that it matches your actual time zone.