MR6500 Pro Power Issues

MR6500-1A1NAS

Firmware: NTGX65_10.01.31.01

Purchased from ATT. 

Troubleshooting steps so far: 

• AC adapter without battery - Device powers on but will not stay on. Removing the type-c from the device and back in makes it power back on, but will not stay on. 
• Device will not power on at all when battery is inserted. 
• If battery is inserted after device is Ac powered on, device turns off. 
• Tried a 2.4A charger (as suggested for other models) but that does not work - image on screen makes it seem like i'm trying to use it with a laptop rather than a charging adapter. 
• Factory reset button does not fix problem. 
• All sleep/power settings have been checked.
• It seems that if I babysit it - constantly hitting the power button to wake it up - then it will stay on. But if I just leave it idle, it shuts off. 

ATT tech support did not try to troubleshoot - only processed a replacement but the unit is currently out of stock. I thought maybe someone here may have some suggestions. 

Thanks!