I have noticed that too. Males are pathetic feeders compared to females. Another thing I have noticed is that although care sheets say male dubias can't fly some that I have held have jumped managed to fly. Not just flutter but fly across the room while going up at the same time. Don't know if I have made super roaches or if they all can do it.
I have been raising dubia for about 2 years now and i have yet to see one do that. I mean i have thrown them at friends and they can flutter a good distance but i have never seen one take off and gain height on its own. sounds like you have some talented roaches.