Custom Link bug

In my main menu I have a menu item called “Our Mission” that is supposed to be a heading with sub-menu items under it. I don’t want “Our Mission” to link to anything so I set it up as a Custom Link with a blank URL. This technique works fine on every other theme I have ever used. But the Experon theme is generating a link https://www.msch.org/our-mission/. There is no /our-mission page so the 404 page is displaying. Why does Experon generate a link for a Custom Link with a blank URL?

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