Man of Honour
This might be a daft suggestion so perhaps wait for wiser advice but if you've gone as far as you can with a strict OHP and are still getting stuck have you tried treating the last few reps as a push press of sorts to get the bar up there and then just focusing on lowering the weight under control?
Very much this. As long as you are doing the push press correctly (i.e. not just OHPing with terrible backsnapping form) this should help.