Read Voicemails

I use Aastra 55i to access visual Voicemail. After reviewing the VM, it does not show as read. The VMs remain as new.
However, when i checked Asterisk voicemail folders, all voicemails are already being moved to the ‘old’ folder.
Although the FreePBX UCP shows the VMs in ‘Inbox’ just as Aastra does.
Any help would be greatly appreciated.