Some days as I drag a window towards an edge or towards another window DF makes the last little jump to join them together, as it should. Some days it just will not happen, the windows just smoothly overlap or go off the edge. Everything looks the same it just doesn't work.

I'm using DF pro 9.5 on windows 10 1809. Using this with an ultrawide so lots of space to do snapping. Also I plumped for DF rather than the monitor manufacturers software to fake Montors etc. Would be great if it worked the same every time.

Any idea what is not right here?

Unfortunately not. However I have now rebooted and it is working again. It is a little less than solid though when it happens with windows sort of "joggling" when I get close rather than smoothly snapping. Sometimes as well the snap point is 1/4" infront of or over the other window depending on if it is coming from left or right.

It is currently set to 30. Is that too big?

Thanks Keith. I will give that a try. The problem was more pronounced when using this on my ultrawide than on this two monitor setup. I guess it could also be the system itself struggling with the graphics processing?

Okay, turning off Application snapping does not seem to have changed much. This morning I was trying to snap to the top of the window and it was jumping above (to the higher two monitors) and to the right.

I did a video and sometimes it worked, sometimes it didn't sometimes it jumped off massively. It is only a couple of minutes long. The two additional monitors here are on a hub so I wonder if docking and undocking confuses displayfusion?

I will do that and see what happens