stock rooted 4.06.651.9.
What I've done:
Flashed stock recovery
Rebooted into stock recovery to verify it's actually there and such
I've flashed stock recovery twice using fastboot (MD5SUM verified on the stock recovery, downloaded from two different sources)
I reboot into the phone OS and it prompts me to download the OTA 5.03.651.3 update.
Download completes, phone reboots to run OTA update
Phone sits for a while at the stock recovery screen (Device icon with a red triangle and exclamation point)
Phone reboots into OS and has not updated anything.
Cycle repeats, upgrade prompt, download, reboot, again...again....
I'm not a complete noob, but I don't know where to turn next except to just run the older RUU I have and let it start taking OTA updates from a few releases back.
Or would it better at this point to just flash TWRP again, find/flash firmware and 5.03.651.3? I have my data backed up, but I'd really rather not have to go about restoring it again if I can help it.
Can anyone provide any possible insight on this? Feeling a bit lost.