I've seen many posts where answers are provided yet none are accepted. These include questions where the given answers are straightforward and clearly correct.
For instance, in this post, two answers were provided in the day of asking the question. Both answers are correct with @StrongBad's one being an acceptable direct answer (IMO). Yet the post is nearly 3 months old.
It could be that the OPs could have forgotten the fact that they even posted those questions.
What to do in such cases? Could we just report to a mod to accept a correct answer for such posts?