WiFi connection without internet disconnects after some time

[Maho38]

I connect from my mobile device to a wifi gateway without internet access. The wifi gateway is also connected to a raspberry pi and I can send data between my app and the raspberyy pi successfully. But after a while my mobile device or my app is getting disonnecting and I have to reconnect. In my case it is only an android issue.

I have tested it on two devices. It seems that newer Android versions have this problem more often than older versions - Samsung M20 with Android 10 rarely loses the connection, but Google Pixel 5 with Android 12 has lost it often and with Android 13 it is even more frequent!