Outlook for Mac 2021 Issue

Hi all, sorry to impede on your day. My first post and really hope someone can point me in the right direction.

I have Outlook for Mac installed on my M1 Max. Anytime I receive a email from my hotmail account, my username icon is just a solid red when it should be my initials. I have gone into the account and change the icon and everywhere else the new icon is being shown but not in Outlook. I have removed the account and re-added it, same result.

I am hoping someone can point me in the right direction to get it sorted.

Many thanks

[Edited by Moderator]