Call forwarding icon not showing on iPhone 6

On my iPhone 6, I set call forwarding and the call forwarding icon shows at the top left.I restart the phone and the call forwarding icon does not show. However call forwarding is still on at the carrier level. If I go into call forwarding in settings it shows that it is on and then the icon shows again, apparently merely because I have gone into call forwarding in settings. (I am on AT&T.) I have done a network settings reset. It didn't help.

This was not a problem on my iPhone 5s with iOS8 installed.

Anyone know why the forwarding icon is not showing when I restart the iPhone 6?