How to selezct B28 band


I have an EP06 with Rooter system. It works fine. I have tried to see how to force B28 but I don’t understand how to.
I am approx less than 2000m from 4G cell, the way it works today is B7 all the time, B7+B3 dropping and coming back, and extremely rarely B28, usually alone.
Is there a way I can make the modem prefer B7+B28 ?
With such relatively good reception on B7, wouldn’t B7+B28 be the best solution ?
Can it be it is the operator that switches on and off B28 on this cell ? Because B28 would be first in terms of reception quality ?

Thank you for your kind help

PS : AT result of the command found in help :
+QCFG: “band”,0x8d0,0x7e00000000000000000000000000000000000000000000ff000001a0880800d5,0x0


Hello, thanks for your question
The network standard can be modified, and the modem cannot give priority to the operation of selecting B7+B28, and can be locked in a certain band.