Did you try restoring it using iTunes on a computer or just restoring it on the phone itself? There could be something corrupt in the upgrade that you did when you went to iOS 11, plugging into a computer with iTunes installed and you'll be able to download another copy on the computer and it will then attempt to install the iOS again and could fix a corrupted issue that could be causing issues.
I restored using my computer
I tried that but it is not fixed after the restore also it is acting on the same way
my phone is very slow when comparing to other phones of my same iphone 5s model iam running on latest version of iphone.only my iphone 5s is slow when comparing to other iphone 5s where it runs the same version of an iphone 5s
