Index: src/bp-groups/bp-groups-template.php
===================================================================
--- src/bp-groups/bp-groups-template.php	(revision 11535)
+++ src/bp-groups/bp-groups-template.php	(working copy)
@@ -3878,7 +3878,7 @@
 		$exclude_admins_mods = 0;
 	}
 
-	$search_terms_default = null;
+	$search_terms_default = false;
 	$search_query_arg = bp_core_get_component_search_query_arg( 'members' );
 	if ( ! empty( $_REQUEST[ $search_query_arg ] ) ) {
 		$search_terms_default = stripslashes( $_REQUEST[ $search_query_arg ] );
@@ -3897,7 +3897,7 @@
 		'type'                => 'last_joined',
 	) );
 
-	if ( is_null( $r['search_terms'] ) && ! empty( $_REQUEST['s'] ) ) {
+	if ( $r['search_terms'] !== false && ! empty( $_REQUEST['s'] ) ) {
 		$r['search_terms'] = $_REQUEST['s'];
 	}