
I have solved the issue. See below my situation:
- In a GPO we have set that a user is not allowed to install any extention in Edge. (GPO path : Computer Configuration | Policies | Adminitrative Templates | Microsoft Edge | Extentions | Control with extentions cannot be installed = enabled with a "*" as value.
- De Discover button is now an extention, so that's why the option is grayed out to turn Discover on.
- In the same GPO (GPO Path : Computer Configuration | Policies | Adminitrative Templates | Microsoft Edge | Extentions | Control which extentions are installed silently = enabled. Add the extention id's for Discover in this policy setting.
- The Discover extentions are :ofefcgjbeghpigppfmkologfjadafddi AND nkbndigcebkoaejohleckhekfmcecfja
- After applying the GPO to the device, reboot the device and login. Start Edge and you will see the Discover button enabled.