When I select an area that contains a completely opaque color part and an alpha color part, after copying and pasting it, it highlights the selection for only a part of the selected area.
Also, if the whole selected area is with alpha, after pasting the whole layer it is not selected/highlighted, so I can't work with it!
But the real selection is the whole area correctly, so the color changes if I paste it twice.
It's a bug? Or how to make it select all area after copy-paste?
Draw something as full color and with alpha:
copy and paste, see that the highlighted selection is partial:
draw something all with alpha:
copy-paste, see that there isn't a selection at all:
(Gimp 2.10.18 on Ubuntu)