Would like to update here, in response to @alzhao in direct messages as well.
For those looking, the problem was due to a “data block” on the data plan on ATT’s end ultimately due to a “flagged” IMEI that the GL-X750 V2 was shipped with.
What’s a data block?
A data block is a restriction on your data plan that prevents any data from being sent or received from your device with the corresponding SIM card. Often times, support reps won’t even know what to look for if you say “my device doesn’t have internet”, or “it’s stuck on 3G only”. This data block was spotted only by the fourth representative we talked to.
Signs you’re data blocked
The notable signs for us:
- Device stuck on 3G only
- SIM is registered, but no internet available
- Device periodically jumps to 4G LTE, is kicked back to 3G
The solution: (idea from @alzhao)
In Internet > AT Commands, Change the IMEI on the router to something new, such as that of an RUT240 or tablet device using the command below, replacing the numbers with the desired IMEI:
After verifying the new IMEI is active by restarting the modem, insert your SIM card and attempt an Auto Setup.
Test the connection, and if signal is connected, data is being transferred, and the signal lasts for an extended period of time, use the following command to save the IMEI to the device.
Helpful tip: If you get data blocked, just mention to the support team that you are “data blocked”, and they will mostly know where to look.
AT&T may randomly collect device IMEI’s at any time, even when you power a device up. Ultimately, the IMEI that came with our device was “flagged” on AT&T’s end for some reason, and kept adding a data block on each SIM that was installed. Upon following the steps above, the data was restored and flowing smoothly!