I keep finding annoying things in Layout 2020 that are either not fixed or actually working worse. For example, you seem to no longer be able to copy an object and snap to the original geometry. This means that you cannot do things like make 5 evenly spaced copies of a square (by typing *5 after copy) without having at least 2 copies of an object to start with.
I swear the Release notes mentioned that when you drag something the graphics handling is different in 2020. something to do with that Layout will not try to render the complete geometry as you drag.
And also there’s this difference that suggests the elements during drag are representations of the objects rather than true copies of the objects themselves.
I’m not sure how Dave is getting it to work correctly. With 20.2 on Mac and Windows, I get the same behavior you’re seeing. Here is a screen recording of the behavior in Windows. Note that the duplicated object does snap to other existing objects, but not to the one you started from.
I wasn’t able to find an existing issue about this, but I have reason to believe the behavior will be back to normal in some amount of time from now.