Phone acting weird

[AC Question]

I was going to sell my Samsung s6 phone so I factory reset it. When I turned it on again and started clicking the buttons to make sure everything was fine nothing would work. For example, when I click the next button a blue square will appear around it the phone will say "next button" but nothing will happen. When I would click any other word or button on the screen the same thing will happen with the blue box and the phone repeating what it says. I ended up having to double click everything and hold down just for it to go to the next page. When I finally made it past the setup part of the phone it wouldn't let me scroll anywhere and of course the same thing happened again. My phone was perfectly fine before I factory reset it. I tried reseting it again but it didn't fix the problem. I don't know what it could be.