Failed to send message

[scicommAmy]

With one of my co workers, we cannot send Teams messages to each other. If we are in a group conversation, we can send message with no problems, but we can't seem to send to only one another. It keeps coming up as a Failed to Send message. Any ideas how to fix? I can message all other colleagues without issue.

[#2]

Hi @scicommAmy   Did this problem just show up today or have you been having it for awhile? This has happened in the past when there's an outage at Microsoft but another user offered one explanation as the best solution in this past post: Failed to send - Page 2 - Microsoft Tech Community

Anyone else have a solution?