OpenWRT is for a main board. LTE-module inside is of its own firmware. adb shell commands are straight for LTE-module. So it does not matter what firmware is in the main board of router....

Hi, All. I have TL-MR6400 V.1 with OpenWRT v.19.07.5. I cannot set 4G to one particular Band. New V.3, V.4 can set fixed 4G-band via original firmware. The V.2 has three various LTE-module-firmware...