Need help with Silhouette Cameo Fill Feature

This seems like such an easy command, and yet nothing I try is working.  I want to fill only the top part of this journaling card (around the text) with a solid color to print and cut.

I've checked that the horizontal line intersects the outline of the card.  The horizontal line has a thickness.  I'm not sure what else to try?

Thanks in advance for any help!