In Rhinoceros 8, the X, Y, Z plane in the perspective view matches the X, Y, Z plane in the isometric view.
rhino 9 @wim You changed it, but this is a Rhino 9 issue — I don’t have this problem in version 8.
Starting from the perspective view (the axes are correct), I switched to the isometric view (the planes are flipped). In the isometric view I corrected the CPlane, then I went back to the perspective view and the planes were flipped there!!!
Basically, when the planes are correct in the perspective view, they appear flipped in the parallel view, and vice versa… take a look at the video.