Smartlock 4 pro disconnects from server

My lock is configured for Wifi connection. After 5 minutes connection gets lost to the server. My lock is still pinagble on the local network. MQTT connection is still OK. Network reports RSSI -48 , Wifi Quality 3. Server connection: SSE connecting, Wifi disconnected. Switching internal Wifi off and on and configuring again it stays 5 minutes OK. Running the Beta 4.1.1

My Lock is also freqently disconnecting and wont reconnect without manually reconnecting the WiFi. My current Firmware is 4.0.36. When disconnected, MQTT ist Not Working.