T-Mobile WCDMA Connection Issues with EM7455

[brcisna]

Hello All,

Tried to see if i could use a T-Mobile sim from a free hotspot device, into a new Sierra Wireless EM7455 modem
This same modem works fine with a US Cellular sim from a hotspot device,,just for completeness.

When i try the actual TMO firmware the modem is not actually detected as an 'cdc-wdm0 device in modem manager.
When at!rmareset=1 ,, then reflash to GENERIC firmware ,,reboot,the mmcli always shows denied. When i run at!gstatus? the modem is showing up as WCDMA
Why would this modem be set into WCDMA with the T-Mobile sim.
Any ideas?

Thanks