@beingmoody2 Tnx for the reply.
Some more info...
I've added a new interface to pfSense, and put it "directly" in the network/subnet of the DHCP server.
DHCP relay now starts from the GUI(it will probably use that interface for relaying as it's closest to the DHCP server).
I recon this is the most used option, so maybe that is why no a lot of people have problems.
However, I do not want this interface there.
If i disable this new interface from pfSense gui. DNS resolver won't start anymore.