following cursor on the wrong monitor

[PK-Mega-Awesome]

I have 2 monitors and have a display source for my left monitor that i want to do the zoom and follow on. it was working fine for ages, set up with a guide from a youtube video. all of a sudden the 'zoom' only follows my cursor when it is on my right monitor (so if my cursor is on the top left of my right monitor, the source is zoomed in to the top left of the left monitor)

these are the settings i am using: