When copy/pasting text into comments it appears that formatting is kept. This means, for example, if you have dark mode on and you copy some text and paste it in a comment, the text will be white when in comment edit view. When the comment view view is active and in the main reader this extra formatting is suppressed (so the text is black).
Because the formatting is suppressed for display and cannot be edited in the comment editor, it should not be kept in the comment editor at all.