I have iPads with iOS 11.4. When trying to connect to an AP I get an issue with an Apple ID. Also Not capable to receive notifications in this state in any other WiFi than I could test. I need to talk to IOS support team they will tell the process how to get the latest version of IOS, just need to dial apple id support number
and get the solution like this. And having any kind of other problem then get stay with their team always.