I'm using the Marquee with the Rotated Rectangle option in plan view.
After I have completed the rectangle, the marquee is displayed wrong, it still works, just the display is skewed.
In the attached screenshot the marquee is supposed to be parallel to the other elements.
I am glad you mentioned the zoom.
It seems the longer the marquee is, then the lower the zoom factor is that will affect the angle.
It seems to have something to do with how much of the marquee is off the screen as you zoom.
So the more one end of the marquee goes off the screen as you zoom in on the other end, the more the angle of the marquee distorts.
I can reproduce this if that helps - but I can't say it will affect me at all - I have never noticed this till now.
I tested it in version 18 as well as 21, and it is there too, so it has been around for quite some time.
If it doesn't affect the outcome then I guess it will not be a high priority to fix even if you did report it.
One of the forum moderators. Versions 6.5 to 25 Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10 Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10