I have a MacBook Pro running High Sierra, an iPhone 7 running iOS 11 and an original iPad mini running iOS 9. The files sync between my Mac and iPhone and also show up on the iCloud website. I cannot for the life of me get them to sync on the iPad. I've tried doing a fresh install and rebooting, turning iCloud off and on again etc. Nothing works. Did apple break backwards compatibility? The iPad is running iOS 9.3.5 which is the latest and final version.