Opengraph Metadata / flat arrays

I tried to adjust my opengraph metadata as described in the changelog of the 1.0.9 release.

[BC] Metadata now supports only flat arrays. To use open graph metas and the likes (ie, ‘og:title’), simply specify it in the key.

These flat arrays do work for me in the site.yaml and site-wide.
If I use the same notation in the markdown headers, the site.yaml metadata is not overridden.
I tried a few variations, also mixing flat and non-flat arrays across both files but nothing seems to work.

It looks like the section in the docs (Opengraph-Metatag-Examples) has already been updated. So I tried that example too…without any luck.

    'og:title': The Rock

Do I miss something?

Could be a bug. Open an issue on so we don’t lose track of it

here it is:

Thanks will look at this.