Select staff (Optional) can't be turned off

I had the same issue. When I changed the setting in the booking page setup area, it would never actually update the booking page. This is totally unexplainable and a bug in the Bookings software that Microsoft still has not fixed.

Good news: I think I have a solution (worked for me today). You have to go to the "Services" area on the left menu and make a change there, instead of in the "Booking page" menu. Within "Services", you should see at least 1 service item, with a button for "Edit service". Within the "Edit service" pop up window, select the "Assign staff" tab and then you have a toggle to disable "allow customers to choose a particular staff for the booking".

Feedback for Microsoft:

1. You have 2 buttons in different places that change the exact same setting. Turning one to off results in the other overriding it. This behavior is unintuitive and creates confusion for the user. Simplify to 1 button, or indicate the purpose of having 2 buttons.
2. Your buttons are located very deep in the menus in unintuitive places. Either bring them higher up in the menu, or to a different place that makes more sense.
   1. Toggle 1 : Booking page --> Default scheduling policy --> Staff Control --> Toggle
   2. Toggle 2 (4 layers deep): Services page --> Service object --> Edit service button --> Assign staff tab --> Toggle