Double or triple up on your jab. If hes tapping your lead arm out the way and coming over it, you are allowing it. Get more active.

If he likes to push your glove down you could entrap him by leaving it out at a safe distance and when he pushes it down you go with it, then fold your lead elbow over his arm and trap that side of him as you move in throwing the rear shot or come up and around with your lead into a hook if he reacts the other way. Either way your lead can remain above his.

If you were into Mma and facing a southy who likes that downward push, you can resist once so he thinks that way, then next time you release and go with him and fold onto it the same way and move in and walk your elbow straight into their breast or face in one move. If you touch their lead foot with yours on the way in it gives them another interruption thought to deal with too. Worse if you can drag their foot slightly forward with yours at he start or on the end of the move, just a touch does enough.You got a big opening coming up. Much different set of can and cant dos when someones right foot is out there right next to your left lead foot.