A fix has been deployed and validated and we are monitoring the results.
Posted Dec 21, 2020 - 02:38 UTC
Update
We are continuing to work on a fix for this issue.
Posted Dec 21, 2020 - 00:22 UTC
Identified
We are investigating an issue with new signups selecting a username that is impacting all Bitbucket Cloud new signups. We will provide more details within the next hour.