How is the shared mailbox added to Outlook? As long as it's added as additional account (via File -> Add account), any flagged messages should appear in the Todo list on the Task pane.
I'm pretty sure this is by "design" for automapped mailboxes, configure it as additional account instead if you want to take advantage of this (and many other) features.
@Vasil Michev configuring shared mailboxes as additional accounts used to work for 1 or two shared mailboxes but I had bad experiences when configuring + 2 shared mailboxes as additional accounts.
Eventually I found out that creating a different outlook profile is the way to go to add multiple shared mailboxes with full functionnality.
