This is a manual step required if you use mobile apps for your work data.
For Most Mobile Apps (Outlook, Teams, OneDrive, Word, Excel, etc.):
Open the App: Launch the specific Microsoft 365 app (e.g., Outlook, Teams).
Go to Settings/Profile: Look for your profile picture, initials, or a menu icon (often three lines) within the app. Tap on it to open the settings or account options.
Sign Out: Find the option to "Sign out" of your work account. Confirm if prompted.
Sign In with New Credentials: After signing out, the app will typically prompt you to sign in again. Enter your new Office 365 work email address and password.
Restart App: Close the app completely (swipe it away from your recent apps list) and then reopen it.
If you continue to have issues:
Uninstall and Reinstall: Sometimes, the quickest way to resolve persistent problems is to simply uninstall the problematic app from your device, then reinstall it from your device's app store (Apple App Store for iOS, Google Play Store for Android). You will then be prompted to sign in with your new credentials upon first launch.