When docking panels into lateral bars, windows become auto-appearing when the 
mouse hovers on; for example, dock on left bar the Files panel clicking on the 
upper-left "<[]" icon, then pass the mouse over its name to make it appear, 
then right-click on any item to display the context menu: when passing over 
options in correspondence with the panel right border underneath, the mouse 
pointer becomes the horizontal resizing form "<->" instead of remaining the 
standard arrow.
this maybe happens because the context menu ignores the fact the it is in 
foreground respect to the panel border.

I hope I could make you understand this little bug...

* warm regards *