What firmware version(s)?
You have to have ...16236... in order to use the new DTTW functionality.
If you need to flash your phones with WDRT, do it now, before you configure things, save yourself some headache ;-]
Oh yeah, are you still selling the second one? I may be looking here, wondering what your bottom is, PM me if you want.
My wife is still griping about the M8, running W10m, it hangs a couple times a week, which is twice too many in her book (my daughter, on my old 1020, hangs maybe once/month, much more stable, go figure;-]).
Either way, sell it soon, I see them on eBAY (950, new) for about 295-310, free-ship, currently, been watching, trying to decide...