I can't download (update) files in iCloud Drive on my iPhone 6 over 4G connection. It only works with WiFi. Can someone help me? Thanks.
Please see this image which shows you how to enable cellular data.
This happens when cellular data for iCloud is switched OFF:
- Go to Settings
- Select Cellular
- Scroll down to the bottom and switch ON the ICLOUD
By doing this, you can now download files from iCloud using cellular data.
I had the same problem on my iPhone8 and got it resolved with Apple Support. Apparently, while the settings (mobile data on, iCloud enabled) may be correct, the phone may not detect them correctly. The solution is to turn mobile data off, shut down the phone. Start the phone up again and then turn mobile data back on. Shutting down the phone must be done differently for this to work. Press volume down, press volume up, then press and hold the power button until the apple logo appears.
The way I solved that issue is to logoff and login from icloud and turn plane mode on for 30s. See https://discussions.apple.com/thread/8246057.