Just an update. A couple of weeks ago, I updated the router to the 3.211 firmware. The connection speeds didn’t seem to change, and I still kept receiving the nagging warning message about the Feb 22 3G sunset message in my AT&T online account. Feb 22 came and went with no difference in the internet behavior, so I was hopeful that maybe this whole situation had been an unfounded fear.
Unfortunately, night before last, my internet connection went down. I checked my AT&T account and this single line (out of a multi-line family plan) had been suspended. I spoke with customer support on the phone and they were adamant this device’s SIM was not going to be supported by the ongoing network upgrades. (These lower level tech support folks don’t understand the technical explanation that the router is connecting to a 4G tower vs 3G. All they know is what their system tells them when they enter my SIM number.)
AT&T is sending me a free phone in the mail that I’ll try to tether with while I attempt to figure out an acceptable solution with the Spitz. I have no idea if other GL-X750’s have been affected yet, but I wouldn’t be surprised if AT&T slowly starts removing them from the network over time. I hope the team at GL.iNet will continue to investigate this issue and work to find a solution before even more people are impacted.