iPhone won't let me pick up calls I have an iPhone 5S which I recently upgraded to iOS 10.0.2.

Since 10.x, when I receive a call I cannot always answer it. The calls appears on the display with the swipe-to-answer widget, but the widget is non-responsive. Swipe all you want, nothing happens, and the caller eventually gives up.

The same is now occurring on my wife's iPhone 6. It is very frustrating! Anyone else seeing this and/or have any suggestions?
Apparently the problem is not the phone call per-se, but the new notifications screen. It seems there is a notification on top of the slide-to-answer, even though you can't see it. Yesterday's iOS upgrade fixed it, everything is working now.