@leocg I don't know if I am doing it wrong but I can't update the media package because the 1903 is not compatible with my Winver 20H2. I think I need to wait until a new media package is out.
Edit : I just installed the package through "Apps > Apps and Features", using this guide: https://winaero.com/install-media-feature-pack-for-windows-10-version-20h2-october-2009-update/
This resolved my issue!