Fix to Apple ID sign out being greyed out
a lot of people have this issue, here is how to fix it. Do a back up of your phone, wipe a i phone you don’t use anymore, download your the back up onto your old phone, once the back up has successfully downloaded onto old device(for me was an I phone x), connect problem I phone to a Mac, then put your problem device in recovery mode ,then go into your Mac and click restore I phone, once that is complete you should see a locked to iCloud notificationon the phone you just restored. Start to set up I phone using your old phone, once you gets to transfer data tab, click transfer from your old device(iPhone X for me) then once everything is downloaded. Your problem should be fixed. I think it is an I cloud issue rather then a phone issue. So don’t use I cloud or don’t transfer data through I cloud back up. Just use the older phone to transfer the data. Let me know if this helps. It worked for me and I was talking to Apple support for months. They weren’t able to fix it. But I was able to figure it out
iPhone 11
