Primary/Seconday band question

With a RM520N-GL is there a way to control which band is primary and which band is secondary? When I first turn router on my primary band is N71 and secondary is N41 and it has great upload and download speeds but after a few minutes it switches to N41 as primary and N71 as seconday and I only get a 3rd of my upload speed.

Dear @Luke_Rowell
Module can’t control which band is primary, the combination is configured by carrier.
Please check your network via AT commands below:
AT+COPS?
AT+QENG=“servingcell”
AT+QENDC
AT+QNWINFO