Name is stuck, not sure if it's a user or not

[Davey Matus]

In our Jira Service Management, we have a 'person' (call it info@companyname.com) that's used also as a email handler

the atlassian environment is connected to our Microsoft 365 AD, and the registered users / agents are from our Active Directory.

The info@companyname.com account has a private name attached to it from one of our colleagues, which, as a result, shows up in any email correspondence to any ticket update. 

I've tried adjusting the name in the Atlassian users, which did not correspond with the "person" in the Jira Service Management project list.

I've tried removing the user from the project alltogether after re-assigning the tickets to this user to another via bulk adjust. Then when i tried readding the user, the private name popped up again.

Did anyone face this issue before? if so, how did you solve it?

Thank you in advance.