Unable to restore Exchange 2010 mailbox in Avamar

I am using Avamar Administrator 7.1.2-21 to restore mailbox data for Legal Hold / eDiscovery requests.Lately when I login with the Avamar Administrator and goto the Backup & Restore | Select the appropriate server | choose the specific backup date | select the appropriate Exchange mailbox DB | Drill down the tree via "Browse for Granular Restore" to find the particular mailbox I would like to restore | then select Restore...

I am seeing at the top of my list of mailboxes for the Exchange Mailbox DB, a list of backed up mailbox in the DB that appear like the below image.

Every time I try to restore a mailbox that has a "(D)" in front, it fails with error.

What does the "(D)" signify and how do I restore these mailboxes? I am already trying to "Recover the entire deleted mailbox".

I'm not sure why it states the mailbox has been deleted, as the particular user was still an employee at the time of the backup and the mailbox would have been active like any other currently active user mailbox.

Can some please provide so info into what this is and how I can recover/restore these "(D)" mailboxes? I have spent countless days/weeks trying to obtain these mailboxes and am my wits end. If the mailbox does not have the "(D)" in front, the restore of the mailbox data to another currently active mailbox on my active Exchange servers works just fine without issue.