When I open the start menu and I "end" it by any other means than clicking on an app to launch or click one more time on the start button (for example, clicking on the desktop). It dissapear without wanting to be opened anymore, a little bit like it stills open and hidden. And it remains the same for the rest of the session

All same with kRunner

So I have basically two chances, after that I have to either restart the session, either launch from terminal

I'm all latest