Root [Help] Did something, no mobile network (no calls, mms, etc)

[c0rsana]

I've been flashing and reflashing my phone for a while now. Recently though it's been wonky. Up until December 25th, I had an old version of Skydragon on it (flashed it just before the M9 was released). On the 25th, I flashed the Cyanogen nightly on there to test out Marshmallow, and noticed that my phone wouldn't revieve calls - no notifications, ringing, etc, just sent em straight to voicemail. I got notifications for texts, voicemails, and mobile data worked fine. In an effort to fix this, I flashed it to the latest stable version (cyanogen 12.1, running lollipop 5.1). The problem persisted. I then reformatted the data partition, then tried again to no avail. This is where I believe I botched things. I then formatted /data, /cache, dalvik cache, and /system via TWRP, thinking that maybe the problem was there somewhere. After that, I installed the latest version of Skydragon (1.6.5 Marshmallow), and it detected no mobile network whatsoever. I reinstalled Cyanogen, same result. Phone connects to wifi, works as normal, but there is no mobile network. No 2g, no 3g, no LTE/4g. I've tried multiple AT&T APNs and tried rebooting / reflashing / re-seating the SIM card, all to no avail. Now, with nowhere else to turn, I turn to you, the wizards of the internet. You guys got any ideas?

TL;DR - HTC One M8, formatted /system partition, can't access mobile network. Halp.

 

[c0rsana]

Update: Phone had switched over to a 'Maritime' Network. Should also mention that the phone was working perfectly on the east coast of the US, but now can't reach AT&T in California, and switched to the above mentioned network. Can make calls and receive texts, but same problem as before - incoming calls go right to voicemail.