Agree with X
However, what you're experiencing MAY be psychological. The fact that you're performing better in one exercise, which happens to be a press movement, could be boosting your confidence with another.
You feel like you're "getting stronger" at push ups, so you could also be expecting to be stronger in your bench.
Confidence goes a long way in all endeavors, especially heavy lifting.
Kind of a long shot, but possible, in my opinion.