Most Helpful Guy
There are many reasons why and those reasons can depend on the nature of the break up. For example if you dumped him, he could still be coming to terms with it and still trying to get over the change of relationship.
If he dumped you, not out of anger/spite, he could be making sure that you are alright because the break up may have hurt you in some way in his eyes.
There could be many reasons but one thing for sure is that he still cares about you. Whether he wants to stay with you, is a different matter entirely.