In my own games I've noticed the "learn joseki, lose two stones" effect a lot - not just for joseki, but for all kinds of techniques. I suspect it's partly that I pick up bad habits from studying; every new tesuji adds a new dimension to my wishful thinking. But also, I begin to lose my sense of proportion; once I understand pushing fights better, suddenly I see the turn on the bottom side rather than the weak group on the top side.
(The best example of this is double ataris. The core 12k skill is reading out double ataris and avoiding them. I've improved vastly at go since then, but I get double atari'd all the freaking time. I assume it's because when I was 12k "don't get double atari'd" was about 90% of what I knew about go, so I devoted much more of my time to thinking about it. Hopefully as I continue to improve, seeing the double ataris will become effortless.)
So even as studying opens up new dimensions of the game for me, I need to play a lot before I can get the dimensions orthogonal to one another.
Anyway, this is a long way of saying that I think you can get bad habits from playing and from studying. Part of getting better at something is unlearning your old bad habits and picking up new ones. It's really just an unavoidable part of being good at something.
Maybe part of the problem is that you feel more mentally stimulated from doing go problems. Isn't a game just a huge collection of interconnected go problems? If you tried to think about it like that, would you have more fun playing?
