Pagemediaselect with multiple attribute

Hi There,
I’m not sure if this is a bug…
When I’m using a pagemediaselect field with the multiple attribute in a bluprint in admin plugin, it seems to work at first. But after saving everything seems lost, an in the .md file only the word “Array” is saved for the given property.

Furthermore, if I’m trying to to use a pagemediaselect (without multiple attribute) in a list, the single select fields are empty and not filled with the pages media-files.

Everything happens in a modular page with the latest versions (grav: 1.1.5, admin: 1.2.2)
Can anybody reproduce/confirm this?