Hi James!
Thank you for your input. The reason we used at!selrat is because it’s what was recommended to us in the linked thread by a Sierra Wireless FAE. Note too at!selrat works as advertised/expected when tried on a different unit. The question in this thread relates not to how to lock the modem to 3G, but how to recover it from this (possibly damaged?) setting on a specific unit.
Nevertheless, we can try at!band too, but it would still leave the question if this unit is in any kind of damaged software state, and if it is, what other consequences it might have in the future. So we’d rather vote for recovering it rather than ignoring the problem and using a different setting. All I want to say is, even if at!band is recommended over at!selrat (though it seems at this point expert opinions differ on this matter), it’d be best to resolve any errors in this unit, which at the moment pertains to at!selrat.