Not able to upgrade to iOS 12 from iOS12 Beta Every 2 seconds I’m getting the notification above 

But when I go to the Software updates’ tab it says: Your software is up to date 

 

iOS Version: 12.0 (16A5365b)
Model: iPhone 6Plus (64GB) NGAH2HN/A
This is an Apple bug that looks like it is fairly wide spread.

Apparent iOS 12 beta bug causes never-ending notifications to update software