This is the error message I am receiving when trying to connect some of our sales team (outlook to hubspot). any suggestions?
Hi @CJohnson911 and welcome, we are so glad to have you here! 
Thanks for reaching out to the HubSpot Community!
I have found for you the solutions from @JOsorio7 and @BBacharz on this similar post “Trouble connecting Office365 Inbox and Calendar to Hubspot, not reaching Outlook authentication” that might help you!
If you are still seeing the same behavior after trying the options in the above thread, I would recommend connecting with HubSpot Technical Support, as Support is included in your subscription and they will be able to provide real-time assistance for this matter, including hopping on a screenshare if necessary.
Thanks and have a great weekend!
Warmly,
Bérangère