fixed: use correct type to edit auto join groups

views/default/group_tools/elements/auto_join_configuration.php

@@ -36,7 +36,7 @@
 
 $group_guids = (array) elgg_extract('group_guids', $config, []);
 foreach ($group_guids as $guid) {
-	$group = get_entity($guid);
+	$group = get_entity((int) $guid);
 	if (!$group instanceof \ElggGroup) {
 		continue;
 	}