Landing Page URL fields greyed out/locked

Summary:

Hello

I’m trying to free up a specific Vanity URL path from an existing landing page so I can reuse the exact same URL string for a completely different landing page.

The issue is that the Vanity URL fields on the original asset are completely greyed out and locked, so I can’t change or remove the existing URL. The landing page was created using the HTML Source Editor, rather than the standard Design Editor.

My intended approach was to update the Vanity URL on the original asset, which would release the existing URL path so I could reuse it on the new landing page.