I've had to "unlock" my developer Apple ID once every 5 days on average for the past three months, and once per day for the past three days.
Each time I do it, I have to perform a delicate dance to navigate what seems to be some kind of request throttling that gives me HTTP 503 responses during the unlock process, making it impossible to complete its several steps. Then my session times out and I have to start over.
I've been trying to unlock my ID for about an hour so far this morning…