When creating content in Plone, each 'content item' gets an Unique ID. Because of this, the link to content will not be broken when your move content or rename (its url).
So, the 'resolveuid' url will 'find the content item that has id 4fd…28" and link to that.
If you create the content manually, it gets a new UID, and the link will not work anymore (since that uid does not exsist anymore'.
I am not sure what is the best approach if you want to create pages manually, but maybe you could make a script that looks up the url of each from the content / catalog and replace them.
Alternatively something like: How to retain UUID when migrating content type?
You could also try googling / this forum 'migrate uid'