dhcp server is often stopped

[flashbackpa]

It happens often that the dhcp server is off, as I can see from the tab:
Start / Stop / Restart
where it's written:
DHCP Server is offline!
(just happened whilst checking for the tab), but I can't find any clue in the logs, so I had to write a bash script to check via nmap if a dhcp server is present in the network otherwise restart via docker command...
How can I help troubleshooting this issue ?
Thank you.

[flashbackpa]

While waiting for a solution, this is how I workarounded it, maybe somebody is interested..
(please note that 192.168.1.166 is my dhcp server, and vmbr0 is the network card configured with that ip, so please change it according to your lan)

#!/bin/bash
while [ 1 ]; do
if ! [[ nmap --script broadcast-dhcp-discover -e vmbr0 | grep "192.168.1.166" | wc -l -eq 1 ]]; then
docker restart glass-isc-dhcp;
fi;
sleep 15;
done