Avoid using the font settings in the rich text editor, as these settings can produce non-compliant results, especially when font size is adjusted (i.e., do not use Font and Size options on the rich text editor). If you have guides where you think these have been used, you can simply copy the text and select the Tx icon to remove formatting.
If you would like to format content in a box, use structured headings and simple formatting for compliant content. Structured headings can be found under the Normal drop-down menu in the rich text editor.