ghost email account on outlook.com

Hi - I have seen this 'ghost account' reported on another thread (something to do with errors in setting up email accounts) and the resolve is to go into windows 10/11 registry. However, my issue is not a desktop one. On my desktop outlook I have the proper email account set up no problem. My 'ghost' only appears in outlook.com - on the sidebar just above my legit account. It is made up of an address which is outlook_D714C67C61195E23.com. Means nothing to me. It has the Microsoft logo on the sidebar but under accounts in the top right it has my picture the same as my legit account. I cannot delete it, and every time I open outlook.com it defaults to that account. This is very annoying as I then have to click on the proper account and wait for another window to open. I have tried to sign out of it, but that means to use outlook.com I have to sign back in (using my proper email and password as the 'ghost' one doesn't exist) and we are back to where we were again.

Any ideas on how to get rid of this?