Update
Anyone having trouble with the latest update? Every time it looks like it will start the update then in a few minutes it says it’s failed.
iPhone X, iOS 15
User profile for user:
Community User
If you are experiencing problems updating, try deleting the iOS Update file and download it again.
First, delete the iOS Update file. Go to:
Settings → General → iPhone Storage. Find the iOS update on the list and delete it.
After that, Restart your iPhone. Then connect to Wi-Fi, and charger, and go to:
Settings → General → Software Update and try again.
Leave your iPhone in the software update menu and preferably don't use it while downloading.
You can find more useful information here:
If your iPhone or iPad won't update - Apple Support