AT&T PMA Wireless charging (Qi now disabled??)

I've had an AT&T LG G4 (H810) since introduction last year.
I've got a number of Qi charging "pucks" and back covers modified with Qi stickers,
and all have been working well - up until now.

A few weeks ago my phone developed the dreaded boot-loop issue - 3 weeks outside of the 1-year warranty.
I chose to have the phone replaced using the AT&T insurance I've been paying for (w/ a deductible).
I received the NEW replacement last week and it has a June 2016 build date (SN:606....)

The replacement phone no longer will charge with ANY of my battery covers and/or charging pucks.
I bought a Duracell Powermat charger to see if that would work (with the Qi stickes/covers) - but NO!!

Assuming this new phone is NOT defective - it would seem that the design of AT&T variant of the G4 has been modified to reject the Qi charging.

The only "official" PMA cover available seems to be from AT&T:
A PURPLE Quickcircle case. For (ouch)

I've been unable to find any PMA stickers (or rear covers) on Amazon, Ebay, Aliexpress.... anywhere !

Does anyone have any experience with Qi charging on a RECENTLY BUILT AT&T G4 ???

OR... anyone know of a source for PMA stickers or covers for the G4???

Thanks for the help!