Install safestrap 3.72 and uninstall recovery, then reinstall it.
Afterwards boot into safestrap and wip everything except your external sd. After that flash the ss certified rom of your choice then flash the att nb1 modules zip. Boot up and youre good to go.
As of 3.72 you dont need to downgrade to mk2 again nor reflash the nb1 kernels through odin.
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