Import .pst into Room Mailbox Calendar doesn't work

I've exported a Public Folder (on Exchange 2010), that holds reserverations for a conference room to a .pst file from Outlook 2013. I've tried to import this calendar into a Room Mailbox (Exchange 2013), and it seems to complete, but the calendar is not updated. 

Now I'm trying to run this command from Exchange 2013 powershell and it's stuck in queued status. The .pst is only 6MB.

[PS] C:\Windows\system32>New-MailboxImportRequest -Mailbox "SmallConfRoom" -IncludeFolders "#Calendar#" -FilePath \\Exchange2013\e$\Imported\SmallConfRoom.pst