There may be a few reasons a device doesn't cache the Client Foilo to your mobile device for offline viewing.

1. Too many images included in the Client Folio.  

While you can load any number of images to Client Folio, mobile devices will only save a limited amount of data for offline viewing. 

Depending upon the number of images included in your Client Folio, you could reach the cache limit for your device.  To avoid this, we recommend using no more than your best 15-20 images in Client Folios. Or you can disable the Offline Caching in the Homescreen Details Section if you wish to share a larger number of images.

2. The mobile device's settings don't allow offline caching.  

In some cases, users may have updated their device settings, which can prevent the Client Folio from saving for offline viewing. Typically, this happens when cookies are blocked.

Here are the recommended settings that will allow your app to cache on iOS devices using Safari:

Do Not Track:      Set to white (green means on, but you want it off)
Block Cookies:   Allow from Websites I Visit (iOS 8 1-10)
                           From Third Parties (iOS 7)