3D FlipBook - Flipbook pages flip upside down when zoomed

This is an error that only happens to some clients viewing the flipbook. I cannot recreate the error on my side but I have screenshots and information from clients: When certain readers zoom a page will flip upside down.

I have the following info so far:

• It seems to happen to some on the 3rd zoom level.
• It happens on all their browsers
• It happens on all pages
• It happens on all the flipbooks that they open on the site.

Most people don't get this problem.