Not able to search user specific contents in Instagram, Earlier I able to do that. It stopped working out of sudden. I was using user search API for that
One more sudden change from Insatagram, User search endpoints are deprecated immediately, with some other endpoints. It's effective from 4th April.
User Search:
GET /users/{user-id}
GET /users/{user-id}/media/recent
GET /users/self/media/liked
GET /users/search
https://www.instagram.com/developer/changelog/
https://newsroom.fb.com/news/2018/04/restricting-data-access/