My manager told me “you’re doing great”… and gave the promotion to someone else

I need to understand if this is normal or if I’m just being naive. For the past year, I’ve been putting in extra effort at work. Taking on more responsibilities, staying late when needed, helping others in the team — basically doing everything I thought would matter. My manager has always been positive. In every review, he said things like “you’re doing great,” “keep this up,” “you’re on the right track.” So naturally, I assumed I was being considered for the next promotion. Last week, the promotion was announced. It went to someone else. And not even someone who was doing more than me. If anything, I’ve been helping them with their work multiple times. When I asked my manager about it, he said something like, “You’re doing really well, just keep going, your time will come.” But that answer didn’t sit right with me. Because if I’m doing everything right… then what exactly am I missing? I’m not angry, just confused. And honestly, a bit demotivated. Has anyone else gone through something like this? Did you wait it out or start looking elsewhere?