Hm, well it sounds like it could just be your triceps aren't as strong as your chest. This could be a simple fix, either focusing on close grip bench, or really pushing it on your overhead pressing.
It might also be a technique issue. Try keeping your elbows tucked close to your sides and then flaring them around the point where the bench transitions from mostly chest to utilizing more shoulders and tris.
If none of that works there's lots of good articles and threads on here about how to train to get through any sticking points in your lift