Help... syncing does not work...missing media

I have about 6 months worth of video projects. Made on a combination of iPad and iPhone. I've enabled sync and sync over cellular. All projects either show the cloud icon meaning they are synced in cloud or shows the device/cloud logo meaning they are both in device and synced.   It a single project will load on either device. All are missing clips. Some have a tiny section or two but 99 percent are gone. None require any further syncing. I have never been able to make this work. I've tried reinstalling and all the normal stuff.

zach