Bug in default next button

Hi peeps,

I am currently facing a bug in which the next button in the toolbar is always skipping the next page.

Note that my toolbar is created from the root panel

Lets say I have 5 page A,B,C,D and E

Whenever I click the next button, the workflow will be as such

A->C->E->A. Skipping B and D in totality.

I am wondering if

1) how does the default next button knows which page is next in line and

2) where do you even configure the default next button?

Thanks in advance.