Did not receive Unlock Confirmation Email, but receive "We had to cancel your unlock request" email
I submitted unlock request successfully. Didn't receive the email that contains a link to confirm the unlock email. However, I received "We had to cancel your unlock request" email that says "Looks like you didn't confirm your request." and suggests "submit a new request when you're ready to try again."
So resubmitted a new request using a different email address, but still doesn't receive Unlock Confirmation Email yet after 12 hours.