The Joomla Websites
From Joomla! Documentation
Report a problem for The Joomla! Domains
Website managers time is in extremely short supply. Please do not contact managers directly. Issues for joomla.org and subdomains can be created in a number of issue queues.
If you want to update, content, functionality, report a bug, please search all Joomla.org issues first. Most of the times an issue about the problem you've encountered already exists.
If you are absolutely sure there is no existing issue about a problem you want to report, you can create an issue on GitHub to one of the following: