In my previous Solidworks versions when I would mate a face to another face, the part would just shift over to the new specified plane, and not change any other orientation.
See how the part just shifted from left to right? That's what I want, and what used to happen in my older Solidworks (I just manually put the part there as an example)
Now see what's happening when I try again, same face to face selection... yes it mated to the face, but it also shifted the part up instead of just moving from right to left...what is going on???