@MicHes
Hey i have same problem. I use qt 6.3.0 pyside6.
This bug occurs when you open new dialog and set atrribute qt::WA_DeleteOnClose

For temporaly i fixed this issue, i removed this attribute and set all dialogs like a main class attrubute.
So dont remove any c++ object and it ll fixed but i think its awful fix. I need solution too but i couldnt find anything about this.

BTW, next time, please give your thread a meaningful title. Also choosing the best fitting subforum is highly appreciated. And when your problem is solved, mark the thread accordingly. We have a small visual forum guide for newcomers: Hitchhiker's Visual Guide to the Qt Forum and there is also the Forum general guide. One more thing: The image upload feature on our forum is broken, see How to insert image on this forum for a workaround. :-)