
I don't know how you are putting him into the down. The easiest way for an upright down is to put the dog in a stand, not a sit, put a treat on his nose and take it down slowly between the front legs towards his chest until he goes down. He should be upright at this point, then slowly move the treat forward on the floor, he should then creep forward. Just one movement forward, give the treat and slowly build up the distance.
It is a bit difficult to put into words, a couple of things to remember don't laugh if it all goes wrong, just put him back into the stand and start again. Also, keep the movement of the treat smooth and even in speed.
Good luck
Sandra