[Q] D851 AOSP5.1/CM12.1 Data issue

Hey guys I tried to dig before I asked this but:
Has anyone been able to find out why when a 5.1 ROM is flashed data doesn't work?
I have a 5.0.1 ROM working but anything above that won't cooperate.
Voice mails come in but all I get is the "!" On the signal icons.
I've flashed 3 radios that work with T-Mobile.
Tried all metro / T-Mobile APN's ipv6 and 4
But to no avail.
Any ideas?

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