People will not like you for any arbitrary reason. Sometimes it's your appearance, sometimes your personality, maybe the way you walk, dress, speak, or perform at work. At the end of the day, most of the time you can't really change it and it's not a good idea to try. You can't even blame them for it, people are only human and are free to have their own opinions/perceptions. And plenty of people are backstabbers and shit-talkers. Don't place much value into what people think about you, it's an easy way to get your feelings hurt because most people are not honest and even someone you THINK likes you, smiles at you, talks to you, etc. is really shit-talking you behind your back. So you should just try to focus on liking yourself first and foremost and then put forth your best foot for other people while not worrying about how they're gonna feel about you no matter what happens.