With zerg, If you have a set of units selected with an egg in the control group, and the egg happens to be highlighted, as if you had tabbed to them. When you attack move, all your units will move command to the target destination instead.
If you tab to any other units the behavior does not occur.
I can see why this might happen since you cant A-move eggs before they hatch. But when the egg is part a group with other units, the ‘attack move’ button is still available on the command card, and it makes it appear as if you’re a-moving your units, when in fact its move command.
This might occur with other races, if you accidently have a structure/unit that cant attack selected with other units, and you’re tabbed to it, but i haven’t tested anything besides the eggs.