LB1120 and ATT SIM Weirdness

- I have been using an LB1120 for Internet service for almost 2 years now 

- We live in a rural area and there is no alternative in our development

- About a month ago took my LB1120 over to a neighbor and set it up (with my SIM) to do a proof of concept showing that it kicked HughesNets ass. It did. The wife works from home and HughesNet isn't cutting it.

- They ordered the stuff and I lent them a phone so they could get a SIM by adding a line to their ATT unlimited + plan (not premium)

- They have a Netgear Nighthawk wifi router

- Stuff came in, they got the SIM - the husband installed it all and got the Amber Power light

- Couldn't get that SIM to connect to the cell network

- They called me, I went over and ulsing a laptop I put the LB1120 into Bridge mode, all else looked good, except that SIm that they just got from ATT and was in the LB1120 showed 3G and it was hetting 3 bars of signal (-97dBM)

- I took their LB1120 to my house and using my SIM connected to the network at 4G LTE - so the box seems good

- Went back to their house and fiddled with the SIM adapter thinking it was the culprit (4FF to 3FF adapter)

- Used a laptop to connect to the LB1120 UI again with his new SIM - still said it was 3G

- Tried other SIMs from their 2 other phones - still solid amber light - UI said 3G

- Tried the SIM from my iphone in their LB1120 using the adapter - it connected to the network - light went Green and the UI showed 4G LTE

- All their phones report that they do get a 4G LTE signal so it doesn't seem to be a tower issue

- Was toying with the idea of taking the issue to ATT but that will probably be a last resort, thought I would check here first.

 

Any thoughts on this would be greatly appreciated.