You might be overtraining. When I trained in BJJ and also tried to weight train as well as cardio I felt the difference between drinking or not. But that largely went away when I stopped trying to do so much. Other health markers improved as well (sleep, RHR, etc.)
Just a thought if you're noticing a single drink that much.
I have been doing it for a number of years now. My limit is what I can do while maintaining great deep sleep, etc. I can occasionally push harder, but then sleep and overtraining creeps in. So, I am staying somewhere comfortably under that overtraining threshold. Even minimal alcohol consumption starts really messing things up :)
Just a thought if you're noticing a single drink that much.