fix: reject unrouted messages without seq

server/db/mysql/group_message_shards.go

@@ -138,6 +138,17 @@ func groupMessageTablesForSeq(q sqlx.QueryerContext, ctx context.Context, tenant
 			return nil, err
 		}
 	}
+	tables := groupMessageShardTablesForSeq(tenantID, routes, seq)
+	if len(tables) == 0 && cached {
+		if routes, err = groupMessageAllShardRoutes(q, ctx, tenantID); err != nil {
+			return nil, err
+		}
+		tables = groupMessageShardTablesForSeq(tenantID, routes, seq)
+	}
+	return tables, nil
+}
+
+func groupMessageShardTablesForSeq(tenantID t.TenantID, routes []store.GroupMessageShardRoute, seq int64) []string {
 	tables := make([]string, 0, 2)
 	for _, route := range routes {
 		if route.MinSeq <= seq && route.MaxSeq >= seq {
@@ -146,7 +157,7 @@ func groupMessageTablesForSeq(q sqlx.QueryerContext, ctx context.Context, tenant
 			}
 		}
 	}
-	return tables, nil
+	return tables
 }
 
 func groupMessageAllShardRoutes(q sqlx.QueryerContext, ctx context.Context, tenantID t.TenantID) ([]store.GroupMessageShardRoute, error) {