Constant authentication problem within app after second connect


I have a reproducable connection issue with the pan camera:
After successful connection first time, every other connection fails during authentication steop (2/3). The blue LED at the camera remains on, indicating no problem. The app recommends then to restart the app or the camera, which is obviously not a long-term solution.
I’m running the camera together with other devices on 2.4 GHz WLAN with WPA2. Meanwhile I’ve also tried to downgrade the camera to x.223-firmware, without any change in behaviour.
I also doubt that it is a WLAN issue at all: beside having also other IoT devices and cameras working on the same WLAN without any issues, it is possible to restart the camera via the app(!). After that, the camera is clearly rebooting (initial 360 move etc.) which would not work, if it would not have a network connection at all.

To me it looks that either the camera itself or maybe the app is not able to build a streaming connection under certain circumstances, which seems to be a software issue.
Is there any debugging on the way?

kind regards