I use 912UAG-2HPnD with Cinterion PLS8-E (LTE module inside), ppp-client mode.
After reboot LTE module use only 3G mode with signal -55..-63.
Module go from 3G to LTE mode in ~30-120 minutes after reboot.
How to troubleshoute the reason of this non-LTE long time mode?
(Russia, Megafon)