I am kinda confused. You are saying that DNA M is too soft and because of that, you net the ball. Up to this point, I thought and felt that hardness is not directly related to the arc of the rubber. And I would assume that with more direct rubbers you would net the ball more easily. What I thought that sponge hardness is more like `required power to use the rubber`. From my experience and beliefs, harder rubbers required more acceleration to use them properly and spin the ball not necessarily gave more or less arc. I also experienced rubbers in very similar hardness, Tenergy 05 (bought it second hand, booster effect wore off, in Butterfly Scale it is 43, but in ESN scale its somewhere close to 48), EL Pro 48 and Vega X (47.5 degrees hardness) which were very different in its behavior and had different properties. I felt Vega X was direct in most of the strokes, Tenergy had a high arc on brushes and medium on hits and EL Pro was somewhere in the middle (I had limited experience with this rubber). With Tenergy I initially overshoot the ball on brushes but adjusted quickly. With Vega X I landed good brushes but had issues adjusting hits. Keep in mind that those are only my experiences and are related to my technique and blade (Dyjas Ultra Power, thin clipper clone), you might get different results.
I think that there might be more reasons to net the ball than that the rubber is too soft. When you net the ball you either missed the timing or the ball shoot of the bat too quickly without giving it high enough arc (which is correlated with rotation and momentum). Most often when I net the ball I want the point to bad and hit through the ball too flat or strike the ball too early. I think it would be beneficial to see you play as carl stated. Maybe you indeed bottom out the rubber and need something harder, but maybe you want to get something harder indeed. According to yogi_bear review, DNA Pro M is about 47.5, which is the same as the rubbers I mentioned before. Of course, perceived hardness is different than measured, but I think that said 47-48 degrees is a sweet spot for backhand.
Working on ball contact timing helped me more, than switching BH rubbers (I am sort of big EJ...) in terms of putting the ball on the table and not in the net neither off the table. Maybe if we could see you play we could elaborate more.
When it comes to rubber you already have I bet for 05. If you want something new Gewo EL Pro 48. It is a good rubber, made in the new thin top sheet thick sponge design philosophy. Maybe a thicker sponge will be harder to bottom out for you.
EDIT: I would like to add that all rubbers mentioned in this post are considered equal by me. They are just different flavors that may suit different people. I think that Vega X might be more suitable for FH play, but other than that, they are all very good. Also, the latter two (X and EL) are very affordable (I paid for them 20€ and 30€ accordingly for new sheets).
