Petsfanatics Forums - Corgi is confused, Where exactly to poop

My 6.5 month old Corgi has already been housebroken.
He knows to do all his pee and poo business in his pee pen and has been doing so for more than a month.

Then... we started to bring him for walks (after his last vacination).
He started to poop during his walks and this is where the problem started.

Now he seems to have forgotten that he has to poo in the pee pen.
Now he poops whenever and wherever he wants in the house.
We continue to discipline him as we did while housebraking him last time but so far its been 3 weeks and its still no use.

Best thing is he seems to know he did something wrong after he poop outside the pee pen. With guilty feeling he would self punish buy running back to his crate and not coming out even if we call him.

There's no problem with his peeing as he has yet to pee during his walks.
Right now he still knows to go to the pee pen to pee.

Anyone can advise or have similar experience?

Its like now.. after starting the walks... he is confused whether he can poo freely (like in during his walks) or he has to go to the pee pen to poop.