Hello! I had a similar issue with a Brazillian gateway and Raspi 3. if you type
sudo monit summary
you will probably find out that ConcentratorD service is not running. Then type
sudo tail -f /var/log/messages
and check if ConcentratorD is continously resetting. If it does, your problem is probably similar to mine. Maybe you can try to adapt the solution I found ( GPIO 7 reset pin busy - Raspberry Pi 3 ) to your Raspi/gateway.