This is related to the “registration required” zoom advanced options.
If you select “No registration required” it creates the meeting correctly but when you try to make a booking it tries to register the booking with zoom wich returns an error because that is disabled.
If you select “Registration required” it works as long as the wp user has an non empty Name.
I think it should work in both scenarios. In my case I need to keep bookings just in WordPress to keep it simple for users.
Thank you.