As per https://confluence.atlassian.com/bitbucket/publishing-a-website-on-bitbucket-cloud-221449776.html , publishing webpage now returns 400 Bad request when special character is used as the username.

This was working before, and this sudden change is impacting user operations.

UPDATE: Re-opened this bug as a new customer has reported this. If there is a special character in the workspaceID, Bitbucket Cloud should work around DNS hostname restrictions and either accept HTML-encoded characters in the URL to display the page, replace the special characters with "-" (this is supported by DNS) or support custom repository hostnames:
https://jira.atlassian.com/browse/BCLOUD-11257

Workaround: Changing the workspaceID to remove the special characters will make the webpage work, but requires considerable effort (particularly for larger teams) to update remote URL's.