Hello Pierrick !
It's true it does not really work. I tried with several browsers. (10 are installed on my Windows10. Not Chrome)

I tried to learn how it works, but there is no help behing the "?".

I wanted to move the "map" album of OSM, dragued it to the bottom of the list. As it was not in line with the others, I thought the move was not registered and I did not see any command or button to save the move. I left the page without saving, disconnected and when I came back, the OSM album had completely disapeared. Neither in previous location, nor the new. I was in panic !

Oh, now, I see it : it was gone as sub-album, under the one I wanted to put it.

Please, give us back the previous system. The album moving is the worst gadget among all the new things in admin, which are not convenient at all. Pretty, sure, but not designed at all to make it easy for end users.