One reason could be lack of interest. If the person's stories are usually about topics that don't appeal to you, like a particular sport you don't care for or a hobby you find dull. Another reason might be if you have a strained relationship with that person. Maybe there have been some disagreements or a falling - out, and seeing their story feels uncomfortable. Also, it could be that you're just too busy. You might have a lot on your plate and simply don't have the time to spare for watching someone's story.
You could try to have an open conversation with them. Just ask if there's a reason they haven't been watching your stories. Maybe it's a simple misunderstanding that can be cleared up easily.
Not necessarily. Everyone has their own reasons and boundaries. If you're not interested in the content or if you're busy, it's your choice not to watch. As long as you're not being intentionally mean - spirited about it, it's not rude.
They might be avoiding you for some personal reasons. For example, if there has been some sort of disagreement or awkwardness between you two. By not watching your story, they are keeping a bit of distance without being too obvious. Another possibility is that they are too busy. Their life might be so hectic at the moment that they don't have time to watch stories at all, not just yours.
Well, there could be various reasons. Maybe he's got some personal issues on his mind and doesn't have the mental space for your stories. Or it might be that he's trying to distance himself for a while for no particular reason. It's hard to say for sure without knowing more about the situation.
In many cases, look for zoom buttons or options within the interface of the app where you're viewing the story. Some might have a plus (+) sign for zooming in.