Hi there, Jane! Welcome back the the forums and sorry you’re running into some trouble here with update notifications.
Is it possible you have a different domain connected to the license key that is running on your site? If you log into this site and head to My Account > License Keys, you can check to see what domain is registered to your license key.
If there is a different URL listed with your license key than the one you are receiving that notification from, then follow the steps outlined in this tutorial to move the license key to the correct site.
Please let me know if this helps. 🙂
Cheers!
Geoff