Try some of the following to see if you can resolve the issue yourself:
  1. From the tenant portal home page refresh your browser a couple of times, then try to logon again
  2. Try logging on using a different browser (e.g. Edge, Chrome, even Chrome Incognito)
  3. Try logging on from a different device (e.g. mobile, tablet, desktop)
If you are stuck on a "Sign-in Failed" page, try just returning to the tenant portal home page (you can click the Home in Place logo, top left to get there).
If your problem is still not resolved, then please collect some screenshots showing the error message in context, and describe the steps that occurred before the error message was displayed.
Mention whether the steps above made any difference.
Then make a support request in your usual manner and let them know you have screenshots ready to send.