Note that the flap to one wall of the pot does not touch the inner side of the wall, but covers and closes off the top of the pot, like soil:
The other trouble that people seem to have is in getting the proportions of the pot to be more in keeping to Herman Lau's specificity.
I finally made my first Sunday at Marti Reis' house (I will blog on her amazing house and puzzle fascination as soon as I can!) where I taught this model at Pam Miike's request.
One of the best folders of this model that I've seen is John McKeever.