Atziri Medallion Bugged cannot pick up medallion as room is closed

The Atziri Medallion did not make a drop noise after she was defeated. I was unaware you needed to pick up the medallion before leaving the room. It was only through searching the forum that I found out it is needed.

There is no way to return and thus I was unable to open the vault chests.

The chests really should just auto unlocking after she has been defeated. This is incredibly disappointing.