If anyone else stumbles acrossed this down the road…
It’s working now. I don’t know what changes I did since the post. I could have sworn all I have done is research since the post was made, and compare settings.
Though… When I found out the buttons work for the client, I went on site, and tested myself. That was the first time they buttons works. I don’t know if the user was misdialing, as in using # instead of *, as the single press of # is Redial.