Using Taskmanager on Fairphone 6 broken

It starts a few days ago. After a while (12 hours or so) whenever i want to switch to the system taskmanager, it does not show my active apps, it shows this:

The screen is blocked, no chance to swipe to the other apps. And i cannot return to Nigara, that does not work too. I have to tab on the lowser end border to get into the app again. Therefor i cannot exit the app.

I do not have this issue wiith the standard-launcher or with Multilauncher. I think that came with an update, somehow. Would be great to get this fixed…