Post title change replaces menu item name

Hi,

I'm trying to write Share your story on the custom image from the header on my contact page. What happens when I edit the page and change Contact (post title) with Share your story, that Share your story then replaces Contact in the menu. So, my menu item is no longer called Contact, but Share your story. The strange part is I was able to make changes like this on other pages. See the homepage, for example.

Thank you,