eventDispatcher->dispatch has the variables in the called method reversed.
When loading /admin/group I get the following error (after applying patch at https://drupal.org/node/3371641)
TypeError: Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher::dispatch(): Argument #1 ($event) must be of type object, string given, called in /var/www/web/modules/contrib/group/src/Entity/Access/QueryAccessHandlerBase.php on line 90 in Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (line 89 of core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php).
Lines 90 and 91 of QueryAccessHandlerBase::getConditions
$this->eventDispatcher->dispatch("entity.query_access", $event);
$this->eventDispatcher->dispatch("entity.query_access.{$entity_type_id}", $event);Should be changed to
$this->eventDispatcher->dispatch( $event, "entity.query_access");
$this->eventDispatcher->dispatch($event, "entity.query_access.{$entity_type_id}");Active
1.5
Code
This problem is fixed within the scope of this issue 📌 Initiative for Group 1.x compatibility under Drupal 10 Fixed , so it is a duplicate.