If you are unable to connect an account or delete an account, you may have a JavaScript error occurring on the page that is preventing some features from working.
How to Find Out If There Is a Javascript Error
Most browsers have web development tools for debugging purposes.
To use Chrome developer tools, while on the Instagram Feed settings page, right click and select “Inspect” or use the keyboard shortcut ctrl+shift+i. Switch to the “console” tab to check the JavaScript console.
If you see red errors listed, it’s likely that these errors are preventing the JavaScript for Instagram Feed from working.
Steps to Fix or Prevent Errors
1) Disable other plugins and switch themes
2) Make sure all plugins and themes are updated to the latest version
3) Clear your browser history to delete any cached files