I met a guy via a dating app and things went well at the start. We met after chatting for a month, and then went out a couple of times in a few public places like gardens. After that, the chats began to dwindle, and he only met me once or twice in more private places. Now, he hardly chats with me. I am serious about him but can't understand what is wrong with him. Please help.— Vinaya

This isn't someone you know very well, because a dating app doesn't really allow you to know a person until you manage to spend a lot of time with them. If the two of you have met just a few times since those first online chats, it's hard to accept how serious you are about him. This isn't to discount your feelings, but only to point out that being serious about someone involves getting to know them a little better, and a few chats don't really allow that to happen. If he isn't  communicating much, it's obvious that he doesn't take this as seriously as you do. There may be nothing wrong with him, apart from a lack of interest in this relationship. If it bothers you, nothing stops you from coming right out and asking him if he wants to take this seriously. You have nothing to lose by being direct and establishing where you think this is going.