I followed the iPad update to 15.2 and everything changed [View all]

First, when I first go to Safari, at the bottom of the screen there are about 8 web images, of all the recent visits, including about 3 of DU, 2 of Yahoo, 2 of Solitaire games etc.

Once I click on one they are all gone. I decided to close all the tabs before I leave the iPad but nothing changed. So I decided to reset everything. These images at the bottom are still there and now I don't need to use the passcode to open it. My iPad is attached to a keyboard and closing it normally would require the passcode to open it again. I am not even sure whether I am using the correct terms here..

How can I bring back the need for a passcode? Not that there are any secrets there; I am using it at home. And... is there a way to get rid of all the mini images of recent visits?

I hope it is not too muddled, will appreciate any suggestions.