Posted a ticket on this yesterday, then closed it after realising I'd diagnosed incorrectly.

Editing step titles in the EasySocial workflow does not work, clicking edit causes infinite loading

The problem is in -

/administrator/components/com_easysocial/themes/default/workflows/form/browser/step.php

There is an error in line 12/13 with the code appearing twice.

* See COPYRIGHT.php for copyright notices and details.
*/
use Joomla\CMS\Language\Text;
use Joomla\CMS\Language\Text;

defined('_JEXEC') or die('Unauthorized Access');

removing the duplicate line solves the problem.