Describe the bug

Navigating to /admin gives a blank screen, in the console I can see a lot of js files that netlify CMS was trying to load were located in the root path, and they 404.
Navigating to /admin/ works, the js files now are loaded from inside the /admin/ path and they are found.

To Reproduce

Navigate to /admin (no slash at the end)

Expected behavior

For either redirecting to /admin/, or to locate the resources correctly.
Screenshots

Applicable Versions:

• Netlify CMS version: netlify-cms-app 2.12.18 + netlify-cms-core 2.30.2
• Git provider: GitHub
• OS: Macos
• Browser version: Chrome 87

CMS configuration

https://github.com/StefanoChiodino/stefano-chiodino-uk/blob/master/static/admin/config.yml

Additional context