Mailbox automatically Pinning every new incoming email - Desktop and Mobile

I have a user that, whenever they receive a new email, that email will automatically pin to the top of their inbox. 

We have tried to recreate the outlook profile

Adjust and create mail rules to not pin emails

Modify settings within webmail

Remove all flags and all disable all setting pertaining to flagging and pinning

Reset customization

reset nav panes

reinstalled office 

Tested in the "new outlook"

On the mobile side, Deleted all mail profiles

Installed the outlook app instead of the ios mail app

made sure he has no specific mailbox retention or policies that would apply a setting like this

This issue has been going on for months with no sign of being fixed. pretty much nothing at all has stuck and the issue persists. I am a systems admin, so i have the ability work on this from the backend. My entire team is just at a loss with this issue.