Markdown & AsciiDoc output filters filter embedded Youtube Video tag / iframe output

Contrary to GitLab's documentation Youtube Videos are filtered in Markdown and Asciidoc output.

As also reported in the forum here and here these instructions don't work:

https://about.gitlab.com/handbook/markdown-guide/#display-videos-from-youtube

Test:

(nothing is shown)

Likewise, the example given to include Youtube video in AsciiDoc also don't work:

https://docs.gitlab.com/ce/user/asciidoc.html#multimedia

video::aHjpOzsQ9YI[youtube]

The syntax which sets a custom title for the video show the custom title, but no embedded video:

video::AX_0XFldFxw[youtube,title=Ralf D.Müller über Docs-as-Code und AsciiDoc,theme=light]