tried again, and done! Now i can select the band :)

@Chalda maybe it s not the modem, but your operator that has this limit.

@Sunshine HI dear same problem of the other user i have MR200 V3, and i m trying to upload the beta firmware for band selection Firmware Version: 1.12.0 0.9.1 v0001.0 Build 190628 Rel.45177n Hardware...