I answered a question that has so far received an acceptance and 11 points. For this I got the Nice Answer badge, but did not get an Enlightened (first to answer and accepted with a score of ten or more) badge. This has not happened to me before. Is there sometimes a lag between meeting criteria and receiving the badge? I thought it was automated. Is there some other reason it was not awarded?
Badges are calculated at regular intervals, not all the time.
Processing badges--especially badges with multiple criteria--takes resources, so the site is automated to check for new badge qualifications at certain intervals rather than running that check constantly.
The next time the site checks for badge qualifications, you'll get yours. It usually takes much less than 24 hours for the jobs to run, but the more complicated the badge qualifications the longer the delay between checks. If you haven't got the badge after 24 hours, then you can be concerned.