Remember, if you and a person and have a conversation where you exchange messages with several sentences, and after a while one party replies with LOL, or thumbs up......This usually means the conversation is over.
IF you reply to them after that and they don't reply back to you, that's your fault. They have gotten up to take a shit, or eat, or have sex......You are no longer impotant and the rules of discourse dictate that you wait at least an hour before expecting a response to another message.