I Can't Permanently Delete Emails From Shared Mailbox

Anyone else had this issue and fixed it? In the outlook desktop app, I deleted mail from my shared mailboxes inbox and sent folder too I believe. In my shared mailbox, under the deleted folder, I select all the messages and click empty folder to try and permanently delete these emails, but then it just readds it back to the shared mailbox's deleted folder. It also creates a copy in my personal account's deleted folder, and when I delete it from there permanently, it still shows in the shared mailbox's deleted folder. 

How can I fix it so I can get rid of these undeletable emails in my shared mailboxes deleted folder?