Hi there! Sorry to hear about this issue. Please try dialing the code as follows *#*#72786#*#*. This is the trigger for certain unlocked phones. Please let us know if you get any response so we may determine a course of action.
I see. We'd like to take a closer look. Please send us a private message so we may work directly with you.
You can send a private message by clicking on my name, then selecting the message option from the profile page.
For the sake of keeping this thread current, I would like to report back that I worked with EdmundM and JoyP on this issue through Private Message. We tried the following:
None of these yielded any changes. My next step will be to use Odin to overwrite the current AT&T firmware version of G935USQU3ARG7 (Oreo) with the Sprint version G935USQU3CSAB (Pie). My hope is that the carrier specific files will allow for Hands Free Activation. I will update later with the results of that effort.