Seeing the viewport frame in widget builder

Hey everyone!

I moved from UE4 to UE5 recently and I want to create widgets. Problem is, i can´t see the viewport frame in my designer menu and I don´t find any solution to that. I already tried to change those in the upper bar of the interface
grafik
(the lock and the displaying the dashed outlines) but it makes no changes. Also I tried to add a border and then on top of it all my widget elements, but those take by default the entire size of the screen and I can´t add more than just two elements in my entire widget…
If anybody has a clue I would be really thankfull it really turns me crazy