A silmilar bug has existed in the command context menu as well for a very long time. However, the occurrence is intermittent and I have no clue how to trigger the bug.
Do a bunch of commands.
RMB in blank window space and choose one of the previous commands that is NOT the very last command.
Intermittently, MacRhiino will not issue the command chosen, rather it will repeate the previous command.
Apologies on the delay in looking at this. It appears to be working as designed to me here although I do see your point. If a right click is performed directly over a non-selected block in the manager, perhaps this should change the currently selected block instance… is that what you were expecting?
In your screenshots, you have a lot of blocks which limits the open space in this area of the block manager but if you do right click in an empty area after a block is selected, you get the context menu for this selected block which allows for an action on it which could be convenient if you were expecting it.