Move between Tab

I just tested your form and it works fine. I can go from any tab to any other tab with no problem.

Let me start by saying that I have not created a multi-page form, so I am speaking from a hypothetical position, but you could either make all (or some) of the fields required. A required field must be completed before the form can be sent, but I don’t know how that works with tabs. You could also look into making each tab inactive until what you want filled out is in fact filled out (soft of like not being able to progress until you accept the terms of service on an application.