If you are unable to find the user on Instagram that you are looking for and getting User not found error on Instagram then there are a few things that you need to follow to fix the “

Not Found” error on Instagram

1. Search username through your mutual friends

2. Use a valid username

3. Send a new message

4. Search profile through other social media

5. Fix your Instagram app

6. Check if you're blocked

7. Wait if you still can or move on

 

For more read - https://onlinegeeks.net/recover-disabled-hacked-or-deleted-instagram-account/