No OTA after return to stock
So while I had my HTC One, I converted it to the Google Play Edition for stock Android. I'm now trying to sell it after getting my Nexus 5, so I restored the CID to stock (CWS__001), removed the tampered heading, returned hboot to 1.44, locked the bootloader (while setting the heading to 'locked' instead of 'relocked'), and return the phone to S-ON. I installed RUU version 1.26.502.12 and it worked without a problem, so it's now COMPLETELY stock.
Problem is, I KNOW there are updates, since the phone is only on 4.1.2, but it refuses to see them when I run AT&T Software Update, and I'm trying to figure out why (also plugged in my SIM card again, to try to run the OTA).
Nexus 5 ~ stock Android 4.4.2
HTC One (AT&T modded into Google Edition) ~ CyanogenMod 10.2 ~ Android 4.3
HTC One X (AT&T) ~ CyanogenMod 10.1 ~ Android 4.2.2
Samsung Galaxy S II GT-I9100 (AT&T) ~ CyanogenMod 9 ~ Android 4.0.4