Edit playback window - now have 2 with higher resolution?

On the edit tab, there is the viewing window where you see the video (apologies for not knowing what this is called!). Theres only ever been the one window there but i've just got a new wide monitor that runs at 3440 x 1440 and now with much more desktop space, if I drag the Resolve program window to make it wider (to see more of timeline), another timeline playback windows appears on the left so I have now have two windows - although the new one shows no video and is just blank.
Is there a way of stopping this second window from showing as the actual window with the video is now pushed to the far right rather than being centralised to the program window?