Error with Provider Hosted App on Edit Form of a list item

We have an error on the Edit Form of one of our pages.

We have developed a SharePoint Online Provider Hosted app which replaces the standard edit form of a list item and has some further events behind the save button. Since this is rather new territory for us, we're using a roundabout way of achieving this by using a script editor web part to display an iFrame of our app. That way we can pass the Url through to our app and retrieve query strings from them.

Our issue comes quite intermittently in that we sometimes get a "web page cannot be found" error or sometimes a "resource cannot be found" error, however, when we load another app on the site (from the same app project, but using an app part), then go back to the Edit Form, the information in the iFrame suddenly renders.

Any ideas on what might be causing this issue at all? Ideally, we should be rendering the app to the Edit Form is the proper manner, rather than scripting an iFrame that points to out app in Azure. Would this be the cause of the problem?

Thanks