PLEASE help me wit 12yo "stepping in the bucket"!!

I have a youngster on my fall-ball team who was hit by a pitch 4 months ago, and ever since, bails out to the point where he's almost parallel to the 3rd base line!!

He's a big, strong 12yo and hits the ball a ton when he connects, but more often than not, he either K's or taps it off the end of the bat.

I work with him every practice...using a 2x6 with the "T", soft-toss and live pitch and he does fine. When I take away the board, I'll put the equip. bag behind him to reinforce his proper stride (which is about 2" and straight ahead). Then without any aids he'll hit just fine...but by weekend game time and the 1st pitch of the 1st game, he's stepping in the dugout again!!

Can anyone please offer up suggestions as to how I can get him to overcome this obvious psychological menace he's dealing with??!!