When rotating a label on a canvas or grid to -90 or 270 deg, the label in preview does not render completely. Look like only part of the label text is rendered.
Try increasing the size of the Label. There are a few quirks with the Rotation property on controls.
I tried making it wider and taller, it did help a little bit still only 30% of the text would get rendered. Thinking of using an image instead if possible.