Is the restore allowed in the policies? Which Outlook version, and what Outlook patches/hotfixes are installed? Is the EV application pool in IIS started? Also see https://www.veritas.com/support/en_US/article.100006408.html
also see below articles. https://www.veritas.com/support/en_US/article.100039979.html
See if you can do the below, I'm not sure about the exact seletions. I can't test, as I do not have mailboxarchiving here.
On the shortcut which does not work. In Outlook, select the tab Enterprise Vault. Select the item which does not restore. Press CTRL+SHIFT, keep pressed, then click on of the EV icons in the EV tab. If correct, you get a popup about EV. There should be a button which opens the properties of the item. Look in there (under section 'selected item') to see where it points to.
Does it indeed point to the correct location? If you copy and paste that location in a browser, does it open?