When a sysop protects a non-existent title from creation, the interface still offers sysops the option to "protect" (instead of "change protection" or "unprotect") the title even when the protection settings have already been applied.
A side-effect is that when the "protect" tab is clicked, the protection form will not highlight the existing protection level. However, the protection expiry time is calculated and populated in the expiry dropdown list correctly.
To reproduce: As a sysop, create-protect any title and reload the page. The interface will show the "protect" tab instead of the expected "change protection" tab.