What is this orange selection on enemies in the Witcher 3

Since I've been playing the Witcher's DLCs I am frequently bumping into the issue where I am 'locked on' to an enemy, shown by the orange border on the level of the enemy. (But I'm not entirely sure it only occurs in the DLCs.) I think I do this by pressing a key combination by accident. What happens, then, is that Geralt starts moving around by himself. He also casts Axii without me telling him to.

I haven't found how to turn this off. Reloading a save game does not stop it, but restarting the entire game does. What is this and how can I turn it off? What is the key combination for it?

Solution 1:

This is the Lock On Target indicator which is activated with R3 on the PS4 and I believe Z on the PC. When this is active Geralt will focus on attacking a single target. Just press the key / button again to switch back to normal mode.