Dear Megan NelsonA,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
Based on your description, you're experiencing issues with your calendar. The error message you're seeing indicates that Teams is having trouble fetching your Exchange mailbox endpoint using AutoDV2.
To troubleshoot this issue, please follow the steps outlined in the troubleshooting link you provided.(Resolve interaction issues between Teams and Exchange Server - Microsoft Teams | Microsoft Learn) This will guide you through the process of checking your Exchange settings and verifying that they are correctly configured for use with Teams.
If you continue to experience issues after following these steps, I suggest you reach to the Microsoft support team for further assistance: Please use the admin account to go to Office 365 Admin Center-> Support-> New Service Request. The support engineers there have the correct escalation channel, and this is the most efficient way to report such issue. You can refer to this article to check the way how to raise a ticket: Ways to contact support for business products - Admin help. The engineers in related team have higher permission and resources than us to help check the root cause from background directly. They can also use the remote sessions to help check/configure the settings for you.
Please understand that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
I hope the information helps! If there is any update or I misunderstand you, please feel free to let me know. I will continue to assist you. Your understanding and co-operation are highly appreciated.
Thanks for your precious time. Have a nice day.
Sincerely,
Sherry | Microsoft Community Moderator