When Group Header template is used and the visibility of an element in the template is changed, the template does not recreate as expected. 

For example add entry /editor in the template and change its visibility

On iOS the editor/entry overlaps the group header and cannot type in it.

On UWP : The editor is visualized as expected but then we change its visibility to false, the space for the editor is still visible. The group header does not layout as expected.

Solution:

You have to collapse/expand the group header so the template in the group header to layout as expected