(Bug) Shelves retracts to quickly (only on externalMonitors, newer macOS)

The drop areas show up when with the dock but immediately disappear. Only if the mouse cursor is right on the bottom edge the drop areas won´t hide. The moment the cursor leaves the bottom line the drop areas disappear. Happens only on my external display not on the built in display. I think it might be due to Global NSScreen Coordintes Rremark: the bottom line of my external display is below the origin of the main display (-200 or something like that). Maybe that´s the cause?