First look at the content of active chat. Maybe a boy who wants to talk to you may not send you a message on his own initiative because he likes you. It is very likely that he has nothing to do now and wants to talk to you. Maybe he wants to talk to you about something, but he needs to ask you for some information. Therefore, if a boy sends a message on his own initiative but tells others that he has not taken any action against you, you should judge whether some things he chats with you are ambiguous love words or consulting you about something. If it is the latter, he may only take the initiative to talk to you because he has a relationship with you.
Second, maybe he doesn't like you or dislike you. If a boy doesn't like a person, then he may find someone who likes him. If you are kind to him, then he is likely to have a good impression on you. Taking the initiative to talk to you shows that he has some affection for you, at least he doesn't dislike it. In fact, when two people are together, heartbeat is not the only determinant. As long as two people don't dislike each other, it is possible to be together. Just like many relationships between men and women, being forced to be together because of the heartbeat is likely to trust and admire each other, and then develop into a relationship between men and women.
Third, maybe he is introverted, and he is embarrassed to admit that an introverted person may have some restraint in speaking and doing things. If a person is introverted, he is embarrassed to tell others that he has a crush on you or likes you, so he is embarrassed to admit it. I know a friend whose boyfriend told others that they were just friends, which made the girls very angry. Later, my boyfriend and girlfriend explained that he was just embarrassed because everyone around him was single and he was embarrassed to be an adult.
Sending you a message on your own initiative doesn't necessarily mean that he likes you, and being indifferent to you doesn't mean that he doesn't like you, so if you like him, you can take the initiative appropriately and don't have to be together.