My icloud back up has a bug that affects my wifi on iphone 7 plus

My wifi has suddenly stopped working on my iphone 7 plus. I visited apple store and when they restored my phone and set it up as "New Phone" it worked again perfectly. However, after restoring from my icloud backup to retrieve my apps and settings the problem reoccurred and my wifi grayed out again.

Obviously, and according to the apple tech support staff, I have a bug in my backup file that is causing this issue, therefore I have to setup my phone as new and won't be able to restore my files and settings from my backup, but I don't want this as I have lots of important settings and files ...

Any way to go around this or other solution? PLEASE SHARE!!