Previously when we were creating multiple UV's we scaled unwanted UVs down and off the grid cos we didn't need them so I find this really confusing
I you look at the image node you will see it says repeat. This means the image is repeated over and over on both the x and y. If you change repeat to clip then it will just be black with an alpha 0 outside of the grid. Hope that helps.
Thank you.
I went to try that out and then this odd thing I've never had before is now happening when I switch to edit mode the object disappears and only leaves a tiny line of dots