The friend tells you about the post that someone threw, but nothing appears to you. Wonder! Surely it "hid" your posts on Instastory, so that you and perhaps other users would not see them. According to an Instagram spokesperson, there is no official way to see if anyone has hidden Stories from you, for privacy issues. However, you can try some other ways:
1. "Collaborators in crime"
Tell a friend to let you know when that user posts something on Instastory. If you do not see the post, chances are you have "hidden".
2. Research
Sites like "insta-stories", which you can easily find on Google, allow you to view stories, even those posted on "Close Friends", without having to sign in to your account. You can always do this if the profile of the person you are going to see the stories with is public.
3. Check again
Someone may have hidden you from a specific post, but not from all the posts of the following days. The reasons? Maybe you know them better ...
Source: Bustle