WiFi not working on iphone 8.. or is it?

Hi

Last week suddenly my WiFi was not connected while being at home.

I went to the WiFi settings, and the WiFi was off. I can enable the WiFi, however no networks are found.

(As a sidenote, im a professional network engineer, my network is fine, other devices work fine, I cant even see the neighbours SSIDs anymore, so please dont take that route, the router is fine and working)

So I opened a case with the store for a repair. For this repair, you have to clear the iphone before sending it in. So I did. After the restore, the phone comes back to the hello screen, and I was curious if the WiFi would work in the 2nd step of the setup. It does! When the phone is cleared, the WiFi works.

So I decided to restore my backup again. Same thing, after the restore, no WiFi.

So it must be a software issue instead of an hardware issue right?

Last step to test is to configure it as a new phone, however this is not really what I want, as I have lots of apps and games where I would lose all my settings and progress.

Any ideas on this issue?

Greetings

Steven