I’ve only found this when the z axis(blue) is rotated off of vertical:
Normally when entities are copied from within a group that has been rotated, the selected entities are orientated according to the axis within that group. This works 100% for groups or components that are nested within the group you are copying from. It even works if your selection contains multiple entities and one of them is a group/component.
However if there are no groups/components within your selection (ie it’s all faces and edges), then the pasted entities are orientated as if the axis was the model axis when the selection was copied.
In the below image, the large box’s surfaces are coloured in accordance to the axis direction a push-pull action would move it. The first smaller box on top of it is a group, the second are individual faces within the group. The smaller boxes in front of the larger one have been pasted - note that the orientation of the colours in the small grouped box changes every time when changing the red/green axis. All perfect until the last box.