Default [Q] Anyone have resolution to "No Mobile Data" issue on Galaxy S3 AT&T?

I've tried flashing different roms, modems, changing APN and mobile network settings, etc. Can't seem to get it to work. Everything else works just fine on 4.2.2, including cell and mms. Just no data.

Flashed (UPDATED):
cm-11-20140319-NIGHTLY-d2lte (4.4.2)
I747UCUEMJB bootloader
I747UCUEMJB modem

Other Info:
Kernel: 3.4.83-cyanogenmod-ge6f22a5 build01@cyanogenmod #1
Provider: PTEL (PlatinumTel, a T-Mobile MVNO)
Mobile network type: HSDPA