Maybe I'm just dumb but my rotation tool in Illustrator seems to confuse degrees and angles. 45º became 90º and everything else just sems off, and when I hit cmd D to transform again it goes back to the original angle. I'm so confused. I added a video that explains it better.
What you set up there is the angle of the axis around which you are mirroring.
I am indeed dumb. I should probably take a vacation haha. Thanks so much.
I feel you.
Have a nice day!