No, you don't need to be worried. It could just be their way of creating distance and it has nothing to do with you personally. Just focus on your own life and move forward.
It could mean that they are trying to move on completely and don't want to be reminded of you. Maybe seeing your stories would bring back old feelings or memories that they are trying to avoid.
It could be that they aren't as interested in your updates as you hoped. Or perhaps they don't use the platform often and missed your stories. Another possibility is that they don't want to give the impression of being too eager or obvious in showing interest.