Nested Symbols Override with Rich Text

I have a “Footer CTAs” symbol which contains 3 “CTA BLOCK” symbols.

These “CTA Block” symbols have a Text Field and a Rich Text field.

I can link the Text Field to the parent’s override field, but not the Rich Text field. Is this a limiation of Rich Text fields or is there something I don’t know?

Where is the “Link to parent” button for this Rich Text in the image below?

Here is my site Read-Only: LINK
(how to share your site Read-Only link)