Instagram has some sort of blocking system in place that blocks Frontends from accessing the data and posts. You may want to try another instance.
Bibliogram is a read-only open source web client for instagram and presents the public profile of a user quicky with their posts. It also supports rss feed.
Use Bibliogram Source CodeSadly, the app developer was requested to take down the app. Now, the app is not in development. But it is still on F-droid.
Get Barinsta Webpage