I'm copying in rich text that has superscript and subscript characters and the rich text editor control does not support this which seems like a bug. It completely removes the superscript and subscript and I can't figure out why it would do this since it's supported by basic html tags.
To test what was going on, I set a text control to this HTML:
hello<sup>bye</sup> world
then I set the rich text edit control's default value to
{{ text3.value }}
and the rich text editor control worked to display it!
So the issue seems like it's on the pasting of text with sub and superscript that the formatting is altered which points to a bug.