I was able to get LTE when i first got the phone, now i am not able to for some reason. Anybody have issues with getting LTE on this phone?
I don't have LTE in my area yet, but I do remember a post similar to yours. The person said they had strong LTE for the first couple of days, then he would get it sporadically. Maybe AT&T just adjusting towers or something. You can always power off bad back on again to provision the phone.
Maybe a daft thing to ask, but is the mobile network set to 4G in the settings?