Outlook meeting request invite loses location when updated

We are using Office 2013 and Exchange Server 2008 R2.  Myself as well as other users have noticed this issue and this is the scenario:

Create a meeting request and add a conference room (setup as a Room Mailbox in Exchange) as a Resource and add users as required and optional (as appropriate).  This causes the conference room to be listed as the location and the meeting invite is sent.

If the meeting invite is update to add or remove users, the room mailbox is now listed only as optional (no longer as a resource) and the location becomes blank.

I know I have the option to manually type in the location, but it's easy for users to forget to do this and (IMO) this is not how the meeting request should function.

Any suggestions on what I can check in Exchange or Outlook?  Thanks!