Expand QTabWidget inside of QScrollArea with QDesigner

Question

I have a QTabWidget inside of a QScrollArea. I need the QScrollArea because otherwise the contents may not fit on a (small) screen. Now I want to add contents to my individual Tabs (like Patients). Therefore I want to expand the QTabWidget more to the right. Somehow this seems not to be possible. When I drag the widget to the right, it is partly hidden, see the picture. [] But I don't what causes this. The same happens when I try to expand my QTabWidget to the bottom. I tried setting sizePolicy on the QTabWidget to "Expanding" but it doesn't help. Any advice? Thank you! 1