Why are the Back and Next button on top on each other?

The Back/ Next are on top on each other.  Please be aware of that this not the case in edit mode.

We are sorry for the inconvenience you have.

I have checked your form named "Web Design START Package form" and seen the issue as the following:

I have cloned the form on my side in order to check its configurations. I have seen that some codes affected the back and next buttons. I have forwarded this issue to our software development team in order to fix it. 

Besides, as a quick solution until the problem will be solved, you can inject following CSS codes in order to fix your form:

.form-pagebreak-back-container {

  width: 70px !important;

}

This will solve the problem as the following:

Thank you very much for reporting us.

Thank! It works.