It may be necessary to place the Smarthome controller closer to the router (even though the distance is not already high).
Even if the Smarthome controller is within half a meter of the router, this may be the cause, increase the distance in this case.
If you have multiple routers, you can put the Smarthome controller best on the Wi-Fi of the first router on your network (the first one on the internet connection).
If you sign up for the Smarthome controller on an additional router, Wifi amplifier or similar device, this may cause the Smarthome controller to not work correctly / stablely.