Warning: array_flip(): Can only flip STRING and INTEGER values!

Warning: array_flip(): Can only flip STRING and INTEGER values! in Drupal\Core\Entity\EntityStorageBase->loadMultiple() (line 264 of /var/www/web/core/lib/Drupal/Core/Entity/EntityStorageBase.php)

I think the error in Drupal\block_visibility_groups_admin\GroupInfo::getActiveGroups() method in $this->group_storage->loadMultiple() invocation. Maybe will be better to use something like \Drupal::entityQuery() to load active groups ids and than load entities by array of ids.