Not working on networks with static IP addresses

[patrickelectric]

I have a pixhawk connected via static IP address and qmdnsengine is unable to find it, but avahi discovery works fine.
It appears that when qmdnsengine is using the mdns group 224.0.0.251 it does not work, but using 192.168.2.2 (rasp ip) or 192.168.2.255 works. Any idea ?