VzW Changing Bands - Kicking device offline

[lpr600]

I have a number of EM7411s embedded in IoT devices. When we initially commissioned them, with generic firmware, they were getting pretty miserable speeds because they were locking onto distant cell sites, or bands/sectors that weren't even aimed in our direction.

After a lot of searching we learned how to create custom band plans, and we would just lock the unit to Bands 2, 5 and 13, and the units would lock on perfectly and give us great (20-30Mbps up and down) speeds. All was good for a year or so,

Then, recently, Verizon Wireless started changing bands at sites and the devices would drop off. For example, we have 2 sites that had great Band 2 coverage, so our band plan was only 2, 13. If we left it at 2, 5, 13 it would lock to some poor Band 5 site. Well, last week in the middle of the night VZW changes something and now Band 2 sucks and Band 5 is the strong one. So, all those devices fell offline.

How do we mitigate this so that a) the 7411 always locks to the strongest band with the best signal and b) allow for the device to search again if VZW changes bands suddenly?

Thanks all.