It might just be that the firmware on the modem doesn't know how to deal with the APN your using, or lack of APN

You may want to use the LP6.

so, its not technically possible to specify which band gets used as the primary band (upload and download) vs the carrier aggregation bands (only download), but ive figured out a neat trick to make it work.

lock the modem to the primary band, but dont specify a second band to lock to. the modem ...