In order to keep this site spam free I approve every comment by hand. This means that comments will not immediately appear after posting.
Unfortunately, comments tend to appear in bursts. There can be long stretches of no activity (where I get nothing but spam), during which I will get lazy and will tend to check less and less often, only to be surprised when there are multiple legit comments waiting (usually after a link has been posted to social media).
So if you think your post got stuck just try again.