Refresh Style when toggle hidden Tab Panel

Hi Community :-)

I load a Grid with a hidden tab-panel (using rowexpander plugin).

When expanding, they have no style like known tab panels.

Trying several things like panel.doLayout() or grid.doLayout() or panel.performLayout() doesn't help

Only changing sorting direction of elements in grid refreshes expanded tab panels shown.

Btw: I use this within JSDuck as Guide-Example-Code. So layout is loaded when clicking "live preview". I think outside this it would work.

Does anybody know what method is called when changing sorting of a col ? I took a look into code of ExtJS, but stopped this because I hope someone has a faster solution. Maybe it is a known problem ?

I searched Forum but only found entries for doLayout() and performLayout() (for Charts) ... doesn't help me

HOPE you can help me to find my way