Right mouse button prevents undo action in softwRe

[Mouth for war]

I've been thinking about this for a while and maybe someone have the answer. Sometimes when I work on something, drawing or modeling, I sometimes accidentally click the right mouse button while holding the left mouse button down. Quite often, I can't undo a change that I might have done when that happens. Stuff that i drew before is restored but not what i did while accidentally clicking the right mouse button.  Does anyone know why it's like that? This happens in different software, so it's not limited to just one program