The user has a test script that includes Microsoft authentication steps, other team members run the script and it shows different landing pages as below, that leads the test case to be failed:
Sign in screen (expected landing page)
Pick an account
Verify your identity
This is the expected behavior of Microsoft authentication when launching the normal browser to execute the test. Thus, the best practice for your case is that using a private mode to execute the test, it will help to clear the environment, credentials and show the expected log-in page to input the username and password field. Besides, we may need to add some delay seconds before and after the failed test step so that the page can have enough time to load the element that needs to interact.
Please refer to this documentation to start browsers in private mode: Start browsers in private mode