When I create a map on the iPhone 12, nearly all the data syncs to the server, except the line of the route itself. I login on a Mac and a Windows 10 PC but cannot see the route line on either computer. Curiously my friend has a new iPhone 12 but does not have this problem. I am using iOS 14.6. He has iOS 14.4.2.
When I create a map on the Mac, it syncs OK with the iPhone.
So I have concluded this is a fault with the iPhone not syncing correctly with the server.
So far, OS Maps tech support has not offered a fix. Has anyone had this problem or can suggest a fix?