Devlogs are reviewed by our admins; they say entries tend to slip off the front page very quickly because people post a lot of them, so that could be why you never get to spot yours there. Our admins are also very busy, so it could take a few days, and unless you happen to look just after they approved your devlog, it's easy to miss.
That said, many creators complain about similar issues. I'll ask again about possible ways to improve the situation.