Chosen Solution
all dpad directions seemed to work fine, until the down button stopped working (left,right and up are fine)
Mathew–There are small tabs on the dpad, it is possible the one on the bottom has broken off causing a miss alignment with the botton on the board. I would suggest using the repair guide to open it up and see if this is the case. If so you can purchase dpads rather cheaply. Hope this helps.
The D-PAD buttons on the Xbox One controller are small metal domes. Sometimes, they worn out and need to be replace. The good news it that they are help in place by a sticker and are pretty cheap and easy to replace. This video should also help you out to do the repair and to install the new buttons : https://youtu.be/qJf9KZ0H1UQ
