icloud backup fail

Try this and see if it works.

Go to Settings>Your Name>iCloud>Apps using iCloud>iCloud backup off.

Completely close the settings app by swiping up from the bottom of the screen, swipe left or right to get to the settings app preview thumbnail and then swipe the preview up and off the screen.

Turn Off WIFi in the Settings.

Restart your phone.

Turn WiFi on again.

Go back to Settings>Your Name>iCloud>Apps using iCloud>iCloud Backup>On>Back up now.

You could try resetting network settings. Settings>General>Reset>Reset network Settings. If you do that, you will have to enter passwords for all of the WiFi networks that you have been connecting to.

Is the device connected to a reliable WiFi? Check the following as well -- If you can't back up to iCloud or restore from iCloud backup failed - Apple Support.

Perhaps you should contact Apple for help now. Use this link.

Get Support

Choose Music, Apps & Services, then choose iCloud, then Update, Backup and Restore and go from there.

Any chance you can post a screenshot of the error message/notification? Blur out sensitive data.

Excellent. Glad to hear that you resolved the issue.

When you're trying to create the backup, are you connecting the device to WiFi?