Joomla is now requiring an upgrade from Joomla 3x to Joomla 4x. 3x will no longer be supported. I'm trying to gather all the infomation possible before I attempt this upgrade. I am currently running CiviCRM 5.51.1.
According to https://lab.civicrm.org/dev/joomla/-/milestones/1#tab-issues it looks like most issues have been dealt with.
You might also get more info in the joomla channel at https://chat.civicrm.org