Logging into outlook.com

Thanks for the response TannerBlaze, but credentials is not the issue. 

I do steps 1-3, get the envelope gif on the screen, and then the browser redirects back to https://www.microsoft.com/en-gb/microsoft-365/outlook/email-and-calendar-software-microsoft-outlook

I then click the sign in link in the top right of that page, it goes to the envelope gif again (no need to enter credentials again), and then back to the URL above.   After multiple times of doing this, I then get presented with another screen asking me which account I want to log in with, where it shows my account, with the words "Logged in" under it.  I click on that option, and then it takes me to my inbox.  So it is not a credential issue, as I only get asked to enter them once

Tony