diff --git a/src/lib/ae_events/ae_events__event_presentation.ts b/src/lib/ae_events/ae_events__event_presentation.ts
index 73a2acf7..d6fe1474 100644
--- a/src/lib/ae_events/ae_events__event_presentation.ts
+++ b/src/lib/ae_events/ae_events__event_presentation.ts
@@ -685,6 +685,7 @@ export async function process_ae_obj__event_presentation_props({
             // Override generic tmp_sort_* with presentation-specific encoding via
             // build_tmp_sort. Order: priority DESC → sort ASC → start_datetime ASC → code ASC → name ASC
             const { tmp_sort_1, tmp_sort_2 } = build_tmp_sort({
+                prefix: [obj.group ?? '0'],
                 priority: obj.priority,
                 sort: obj.sort,
                 fields_1: [obj.start_datetime, obj.code],