How to use UISplitViewController like the Notes app?

I am building an app that navigates through several table views, which contain urls to files that are displayed on the detail side of a ui split view. The iPad app works perfectly, so does the iPhone 6 version. The problem is that the iPhone 6 plus version, when asked to push a new table view onto the master part of the split view, ends up ignoring the push request and placing that table view on the detail side.

I am almost giving up, since I have tried every UISplitViewController delegate method there is, to no avail. I know, however, there must be a solution, since the Notes app does something very similar to what I wish to do.

Here are some screenshots:

1. The start screen is at the right. When selecting, say, the sandbox, the user is taken to the left portion of the picture below:

2. When rotating, however, I get the following artifact:

The master portion is still functional, but the detail now fails to show a document, and has lost its navigation bar.