Undo issue causing accidental duplicates?

[Kal]

I've been noticing that as I work on complex artwork in Designer, I invariably end up with unwanted duplicates of various objects. Since each object is perfectly aligned with its duplicate, I don't notice unless I try to edit, move or delete one of them, or unless I happen to notice them in the Layers panel. I've been clueless as to how these duplicates are being created—I just assumed something about the way I work isn't jibing with the Designer way. (I never had this problem in Illustrator.)

Now I think if I've found the likely culprit—at least one of them anyway. I notice that if I copy an object by option-dragging (a single action), it takes not one but two undos to restore the status quo. The first undo doesn't delete the duplicate object—it just moves it back to the precise location of the original! (See attached screen-capture.)

Is this the intended behaviour or a bug? I can't imagine why anyone would want a single action to require two undos, particularly given the potential for duplicates as I have discovered.

[Pšenda]

Problem with Alt + Drag (copy + move)?

 

 

[Kal]

Yes. Thanks for that. I see the devs have acknowledged it as a well-intentioned,  'long standing bug' and talked about fixing it. But that was back in 2016! Yikes. I guess I shouldn't hold my breath.

[Aammppaa]

I wish this would be fixed too.

In the mean time I've tried to train myself to remove the duplicate by hitting Delete rather than Undo.