Hi Scott,
Thank you for reaching out.
The browser may be using saved sign-in information and opening the personal Outlook.com mailbox rather than your business mailbox.
To resolve the issue, please try the following steps:
- Test in an InPrivate or Incognito window
- Select the three dots in the upper-right corner.
- Select New InPrivate window.
- Go to https://outlook.office.com/
- Sign in with your work account.
- Use a separate browser profile
- Select the profile icon in the upper-right corner.
- Select Set up a new profile > Work or school.

- Select Add, then Sign in to sync data.
- Sign in with your work account.
- Use this profile whenever you access your business email.
If Outlook works correctly in an InPrivate or Incognito window, this confirms that the issue is related to the account session or cached sign-in information stored in the regular browser profile.
I hope your issue gets resolved soon. Any updates would be greatly appreciated.