Wix Bookings - Logout CurrentUser and continue execution and FormFieldValues defaulting to CurrentUser

Hoping someone has experienced the particular issue im having as this is driving me somewhat mad
I have a Wix Bookings event that is a Birthday Party. When a visitor books the party I have a second booking that needs to take place, using an arbitrary email address, to reduce the space in the Pottery Studio for other activities. This works perfectly if no member is logged in.
It fails if a member is logged in and instead of using the Formfieldsvalue i pass to the checkoutbooking() it uses those of the logged in Member every time. When i have attempted to use wix-users.logout() no code runs after this despite it supposedly returning a promise. All that happens is the page refreshes so no subsequent function will run.
Has anyone experienced the overwriting of formfieldvalues in a booking and if so did you manage to resolve it? Has anyone managed to logout the currentuser and continue program execution?
Many thanks, this is weeks of tearing my hair out (I really dont have much left!!!)