Search their username in Instagram
Check whether their profile appears in search results
Open old DMs with them
Look for their profile photo, name, or message history
Try tapping their profile from the chat
Check whether their profile says “Instagram User” or shows no posts/followers
See if their posts, stories, and highlights disappear
Try viewing their profile from another account
Check whether you can mention or tag them
See whether your previous likes or comments on their posts are gone
Try following them again and see if the request fails
Confirm with another account if their profile is visible there