The App Store says I cannot update this app

app has been purchased by my family member and shared with me. I used it for some time, but then disabled family function. I want to purchase app myself now, but App Store is offering me only to upgrade previous version and then tells me that app is no longer shared by my family. How do I purchase this app? There is no buy option and even price is not visible.

[Re-Titled by Moderator]