Choosing Staff

I chose the option to allow the customer to choose staff, however, it does not give the option to choose staff when they want to book. I have cleared cache, cookies, refreshed, used a different browser, turned the choose staff option on and off all in an attempt to get it to give the customer the option to choose the staff and it will not work. I have created other bookings where this option worked fine. What is going on and can anyone help!!!!!