As you are centered on a small area I suggest that you zoom out some and see if you can see anything, the KLM is ADSB as you can see with the globe so should show. As you are zoomed in so much it may be outside the area you are showing. Move the grid a bit to the left as well to make the map area bigger until you can see aircraft then you can move it back to where you like
KLM601 came up over just south of Bishop Auckland and over Stanhope and Allendale so should have been on your map at some stage, I don't know where it was at the time of the shot though.
As you can see from the attached shot you have no range, where do you have the antenna sited, does it have a good clear view of the sky. I don't know your knowledge or your set up but do you have the antenna on a ground plane as this is needed. An easy ground plane is a tin can or biscuit tin lid that the antenna can attach to through its magnetic bottom, try sitting the this on your window sill
Alan