To change the title displayed on your upsell, go to the bundle editor, open the Upsells tab, then:
Click on the upsell you want to edit to open its options.
In the Custom title field, enter the text you want to display.
The title will automatically update in the preview on the right.
You can also use dynamic variables (little person icon) to generate a title based on the offer, price, discount, etc.
If the change doesn’t display or save correctly, contact MoonBundles support.