There are several causes of a screen not sitting securely in the sail track of an AFK

1. The screen is being pulled out of the sail track from the top down, this will release the screen. If you have the screen in the sail track and pull with a downward force as it would be positioned on an awning it will hold. 

Here is a link to a video that shows how the screen will release from the end but hold if positioned correctly. 

Click here to see the screen in an AFK: https://youtu.be/1T29pRNZBJk

2. The Clamps are not tightened - when the clamps are not tightened correctly the sail track grove will be wider (see photo below) 

We recommend following the setup directions fully for setting up the AFK before attaching the screen - this will resolve this issue. 

This is a link to the video on setting up your AFK https://youtu.be/n-Kyi1Ai0jw