Hi Michael,
Thank you for contacting Syncfusion support.
Could you please confirm us whether you are using for RichTextBoxAdv or SfRichTextBoxAdv control for Word processing?
If you are using RichTextBoxAdv control, we kindly recommend you to use the new SfRichTextBoxAdv control since the RichTextBoxAdv control is classic version. Whereas SfRichTextBoxAdv is a new control that works more similar to Microsoft Word, and all the new enhancements are done only in this control. So please prefer using SfRichTextBoxAdv control with all the new features.
For more information, please refer the UG documentation of SfRichTextBoxAdv from the following link,