Exchange Online Meeting Room showing as Unavailable

Hi All,

I've come across a strange issue, the short history I was given is that 3 Meeting Rooms in an Organization were restricted for bookings for a period, however now they want those meeting rooms available to all users.

I cannot find any documentation around what the Admin (who has now left) did at the time to restrict this.

There are no policies in place to restrict users, the only anomaly I can fine is that the Address lists appear to be incorrect.  I have not been able to find out how this happened or a way to resolve this:

I've been through many MS Documents and forums to try and find an answer but have had no insights yet, so figured I would try here.

Meeting Room with no issues:

PS C:\scripts\meetingrooms> Get-Mailbox -Identity "email address removed for privacy reasons" | Format-List AddressListMembership

AddressListMembership : {\Offline Global Address List, \All Rooms, \All Users, \Default Global Address List...}

Meeting room with issues:

PS C:\scripts\meetingrooms> Get-Mailbox -Identity "email address removed for privacy reasons" | Format-List AddressListMembership

AddressListMembership : {\All Recipients(VLV), \All Mailboxes(VLV), \Mailboxes(VLV), \Offline Global Address List...}

Any idea on how I can make sure meeting room7 is in the 'All Rooms' list?   

Cheers

B