Will, work your sticking point with functional isomterics. A description of which is here.
Id personally also recommend some 1.5'S utilizing MxS parameters for about 4 weeks then going back to more basic OHP movements.
Super-strict semi-supinated dumbell presses done seated without arching the back for leverage should also be considered with a 2-3 second pause at the bottom. Make sure the dumbells stay in contact throughout the range of movement which for some means they wont go to full extension.
I also remember recommending using bands to take up your overhead press, Im assuming you are trying them? Because my advice is based on the assumption that you have been using band training.
Dont worry about which specific muscle is weak what are you gonna do about it anyway? Its never that simple anyhow since so many muscles contribute with compound movements.
Just figure out what assistance work you need and train using movements that make you work hardest at and through the sticking point.