There are two styles of air fittings, maybe the other style would work better or not leak for you. Mine doesn't leak at all. I made sure all my quick disconnects are the universal style that accepts either style.
The type I switched to for all my air tools and air hoses that doesn't leak for me looks like this. That way the hose can hand downward so it doesn't stick out which makes the rig easier to handle.
The type I used to use that seemed to leak more as I recall looked like this...
One thing that helped on mine was installing a 45 before the quick disconnect which lowered the fitting's angle so it looks like this one. That way the hose hangs downward instead of out to the side which makes the rig easier to handle and use.