It could be that your account settings are restricting the sharing feature. Check your privacy and sharing settings to make sure they allow for this action.
It could be that your account settings are restricting the sharing feature. Check your privacy and sharing settings in Instagram to make sure everything is enabled correctly. Also, make sure the post you're trying to share is allowed for sharing to stories by the original poster.
There are multiple things you can do. Firstly, ensure your Instagram app is up - to - date. Out - of - date apps can have functionality issues. Secondly, look at the permissions of the post. If it's a brand post or something with specific rights, it may not be shareable. Thirdly, your network connection could be the culprit. A weak or unstable connection can prevent sharing. Try switching to a different network, like from Wi - Fi to mobile data or vice versa, and see if that enables you to share the post to your IG story.
Maybe your privacy settings are restricting it. Check if the post has sharing limitations or if your IG story privacy is set to not allow sharing from certain sources.