Ok I figured it out after getting so frustrated
I use to be able to tap the green phone now, Suprise! I have to slide the green reciver up.
So simple. Samsung why didnt you warn us?
What is the point of this feature? Completely non intuituve. I find it ridiculous that I have to search on a thread just to figure out how to answer calls on a so called smart phone.
Many thanks to all the contributions on this thread.
Thanks you so much for the solution! All of these not-applicable solutions like clearing one's cache, making sure Airplane Mode is switched off, etc., and you figured out that one must swipe UP, not sideways like previous models. The owners manual says to swipe towards the center of the phone, but this doesn't work. Again, thanks for your simple answer!
To set up your phone to single tap to answer incoming calls watch the droid guy on youtube. The title on his presentation is how to fix can't make or receive calls. He will show you haw to set up an assistant which will enable single tap on the green phone to answer incoming calls. It worked and this was after hours and hours trying to get a fix from samsung.