Receiving two of every email from gitlab

As the subject says, I am receiving two copies of every email I receive from Gitlab.
Both emails are going to x@cam.ac.uk, looking at the notifications tab in preferences I noticed that there are global and group preferences for notifications.
I added a second email account (y.z@admin.cam.ac.uk) and set the group notifications to use this, which resulted in one email to each email address.
I then tried disabling the group notifications and still received one email to each address.
I then removed the second email address and reset the group notifications to x@cam.ac.uk while still having these disabled.
I then disabled the global notifications as well as the group.
I then sent a csv export of issues to myself and again received two copies.
I have put the global notifications to Participant for now.

I am hesitant to remove myself from the groups as I suspect this may not be wise.
Can you please help me to receive only one copy of each email?
Do I need to go back to the outlook MAPI to attempt to write a duplicate email removal tool?