I know the difference between left & right clicking, and have used Movie Edit Pro (and other Magix software) for MANY years!
But I find that with the new 2022 version of "MEP" that sometimes when you LEFT-click the + or - buttons in the lower-right corner of the timeline to zoom the software acts as if I RIGHT-clicked it instead and brings up the context-sensitive menu rather than just zooming the timeline!
This bug is driving me crazy as I'm always clicking on the +/- icons while working on the timeline!