When I rebooted my phone today some popup appears which
asked for two keys one for navigating screen controls and other select. I was not able to understand initial objective of this popup and pressed volume up and volume down keys.
After this volume-up key start choosing screen controls like buttons, labels, images with a blue rectangle around. Very same as TAB key behaviour on desktop application and volume down key started behaving as enter key. Volume increase and decrese won't occur with these keys now.
My issue is how to trobuleshoot and bring back these keys to normal functioning. I've installed no application for hardware key mapping and don't want to install a key remapping application without finding this hacking application.
Using one plus three with resurrection marshmallow rom.