Opposed to some of the other devices we support for the BEC router we Strongly advise against Band Locking for a variety of reasons.
The primary reason is that these devices use carrier aggregation and are configured to automatically connect to the best bands for your location no matter where you are. Especially if you are frequently on the move with one of these we advise strongly against it and if you are determined to do so we advise you contact our Tech Support team for assistance in doing so.
If you accidentally enable certain bands to be locked you can always go in and select all bands again.