Browser forcing weird email address and not actual email

[AdminAsist]

So I have Outlook.com email account appears as "outlook_[long series of letters and numbers]@outlook.com" issue, but ONLY in the browser.  I login with my office365 account and when I click on outlook under office home it goes to the "outlook" address rather than the account I am signed in under.  The account is the primary alias already and there is no way to sign in to anything with the "outlook" email address.  It happens regardless of browser.  Any thoughts as to how to fix this?

[#2]

Have you verified your Default From address setting already?
In Outlook.com, choose Settings-> Email-> Sync email

This direct link should also work;
https://outlook.live.com/mail/0/options/mail/accounts

[#3]

@RobertSparnaaij I'm having the same issue on my browser and I tried safari and chrome, both on my macbook - neither worked. The email address is still weird with a long string of characters. I also tried to discard the strange one but the problem remains. 

I'm having a separate issue with the outlook installed on the Macbook itself. It doesn't show the 'New Event' option in my calendar which is why I need to use the account from my browser to send meeting invites and Teams links but then the issue is the email address that goes out. I'm at my wits end and have been trying to troubleshoot all day!

[#4]

@Daniah 

I am having the same issue. I've been trying unsuccessfully to get Teams and Outlook set up under our Family Sharing, but I'm at my wits end!

I've tried Chrome, but typically use Edge.