Mysterious FPS Overlay

I launched PUBG yesterday and, in the bottom right-hand corner of my screen, there was this strange, and obtrusive FPS display that I have never seen before. I launched Skyrim today and it was still there. After fiddling around with nvidia settings and steam settings, I still can't get rid of it.

My graphics card is a NVIDIA GeForce GTX 1060 6GB

Here's a screenshot of the FPS display:
I3dWQlU.png