Does Leo's failure to reply to messages for several days mean that he doesn't like me anymore?

It's possible.

Boys occasionally don't reply to girls' messages. Maybe he didn't see them, missed them, or other objective reasons, which led to his failure to reply to your messages. But most of the time, the boy deliberately doesn't reply to the girl's message, which means that he obviously saw the message you sent him, but he didn't want to reply to you.

The boy doesn't return your messages on purpose. On the one hand, he may be quarrelling with you. Maybe there was some unpleasantness between you, or some of your behaviors made him angry. He wanted to make you realize your mistake by not returning your information during the Cold War.

On the other hand, he may not love you at all. He doesn't have you in his heart at all, so he will ignore your feelings and your existence. Even if he sees you sending him a message, he will feel no need to reply to you.

men who don't reply to messages can't ask for it

In any case, it is absolutely unforgivable for boys to deliberately not reply to your messages. He will do this, at least to show that he doesn't care much about your feelings, or even that he doesn't love you at all, so whether to reply to your message depends on your mood.

Girls don't need to waste too much time on this man. If you don't get a corresponding response to his dedication and love, give up as soon as possible. Maybe when you are cold and want to give him up, he will know that he wants to cherish you.