The issue may be due to a weak connection. If you're near the installed device and have mobile reception, the device should function properly. It can be that your network connection may not be good enough. If you are in the room where the device is installed and your phone has a signal, the device should work. If there is no signal, this may explain the connection problem. The lack of the signal is a common explanation when the water meter is installed in a parking garage or other underground space.
Moving the CPU-Unit to a higher spot or close to the outside wall, window, etc. can improve the connection. For bigger challenges we will provide a new device with a signal strengthener (modem).
The cause of connection problems can also be found in a device that has been sitting in a box for some time before installation and needs updating. To start the update, first unplug the device for min. 30 seconds and then plug it back in. After letting the device update for a while, it should work normally again.