I finley called Yealink support (877-387-2624), and they asked me to email them ([email protected]), and they gave me some very useful steps to take that fixed the problem, see email

Unlike others, I will say that I am getting response from Yealink Support, but they are in China, so interactions with them take days to complete because of the time difference

Other W56Ps that were ordered direct from AT&T work fine.