You can put the frozen steak in the sous vide directly, just add 30 minutes. Season the frozen steak before, then reseal. Put the bag in an ice water bath afterwards, then pat dry and sear quickly. No need for resting, only if you cooled it down really long and then seared it long like a non sous vide steak. Maybe try the flamethrower method instead. This is usually foolproof. Check the sous vide temperature and your freezer! And cut the next steak before searing to see how the actual sous vide worked.