Originally Posted by Nu11u5

If you are checking out the files to analyze them, make sure your phone is not using Wifi. It must be using the data connection to find the server.

It is possible that the websites are IMEI filtered and preventing you from accessing them. I will be posting the update file in the OP when I can.

This link... https://fota.t-mobile.com:443/agents/10475/1001/delta_T939UVIJ6Plus_to_T939UVJA3 ..is the only one that appears to be the firmware update. Until we know what to do with it its not useful though.