Repeat subform does not appear

I have a form which when selecting a checkbox on the first pg it automatically makes several Subforms in Section3 appear. In Section3 I have 11 subforms of which 2 are to be repeated (20 times). I hide all Section3 and all subform 1-11 in order to make the form smaller and only have the subforms the user needs appear when selecting a checkbox.

My problem is the following:

When hiding everything and than selecting SubForm 8 and 9 the repeat possibility does not enable itself. I can see the subform but I can use the +/- buttons of SubForm 7 and Subform 8

I tried hiding only the Section 3 but leaving the subForms (8 & 9) as visible and than it works, which is odd.

Anyone know how to solve this?

I'll attach the form to the documents for viewing.

Thanks!

Nancy