It could be that he's really busy. If he has a lot on his plate, like work, study or other important things, he might not have time to look at your stories. For example, if he's in the middle of a big project at work, all his focus is on getting it done, and he might forget or not even think about checking your stories.
However, if there are other signs along with not watching your stories, like being distant or not making an effort in the relationship in general, then it could be a cause for concern. But on its own, it's not definitive evidence of him losing interest. You could try to engage him more in your social media world, but also focus on your real - life interactions.
There could be several reasons. It might be that they don't want to be reminded of the past with you. Or perhaps they have new things going on in their life and aren't focused on your social media. Maybe they just don't use that platform much anymore.
It could be that they want to avoid any reminders of the past or are simply too busy with their own life to notice. Maybe they don't use the platform as often as you think.
He could be really busy. If he has a lot on his plate, he might not have the time to check out your stories. For example, he could be swamped with work, schoolwork, or other personal matters.
It could be that he's not really interested in that kind of content or doesn't think it's relevant to him. Or perhaps he didn't even notice that you shared the stories.