I've had one issue with iCloud Drive - and that was with Threes. I don't know why/how they're using iCloud, but their instructions to fix it was turning off iCl

I've had one issue with iCloud Drive - and that was with Threes. I don't know why/how they're using iCloud, but their instructions to fix it was turning off iCloud Drive for the app. Other than that, I haven't had any problems. I have seen tweets of people who are having problems, and the most common recommendation I've seen is to turn iCloud Drive off for the app and turn it back on so it regenerates the sync key.