Running Event Booking version 1.5.2
I am unable to change any of the billing field or group member fields show/requirement settings.
Changes made in the back end do not appear on the front end.
For example, unable to remove or even change requirement setting for the "organization", "address" field and others.
I believe you changed the settings in Configuration and It is not the correct way. Changes in Configuration only affect new events. For events which you created before, you will need to edit the event to change the settings.