diff --git a/sqle/model/instance_audit_plan.go b/sqle/model/instance_audit_plan.go
index 158bf99c5..eeb098307 100644
--- a/sqle/model/instance_audit_plan.go
+++ b/sqle/model/instance_audit_plan.go
@@ -176,8 +176,13 @@ func (s *Storage) GetLatestStartTimeAuditPlanSQLV2(sourceId uint, typ string) (s
 	info := struct {
 		StartTime string `gorm:"column:max_start_time"`
 	}{}
-	err := s.db.Raw(`SELECT MAX(STR_TO_DATE(JSON_UNQUOTE(JSON_EXTRACT(info, '$.start_time_of_last_scraped_sql')), '%Y-%m-%dT%H:%i:%s.%f')) 
-					AS max_start_time FROM sql_manage_records WHERE source_id = ? AND source = ? AND deleted_at is NULL`, sourceId, typ).Scan(&info).Error
+	// Compatible with DATETIME(6) (space separator) and historical RFC3339-like values (T separator).
+	// Trailing timezone suffixes on RFC3339 are ignored once the format is exhausted.
+	err := s.db.Raw(`SELECT MAX(COALESCE(
+		STR_TO_DATE(JSON_UNQUOTE(JSON_EXTRACT(info, '$.start_time_of_last_scraped_sql')), '%Y-%m-%d %H:%i:%s.%f'),
+		STR_TO_DATE(JSON_UNQUOTE(JSON_EXTRACT(info, '$.start_time_of_last_scraped_sql')), '%Y-%m-%dT%H:%i:%s.%f'),
+		STR_TO_DATE(JSON_UNQUOTE(JSON_EXTRACT(info, '$.start_time_of_last_scraped_sql')), '%Y-%m-%d %H:%i:%s')
+	)) AS max_start_time FROM sql_manage_records WHERE source_id = ? AND source = ? AND deleted_at is NULL`, sourceId, typ).Scan(&info).Error
 	return info.StartTime, err
 }
 
diff --git a/sqle/server/auditplan/task_wrap.go b/sqle/server/auditplan/task_wrap.go
index ff4c03933..88975669c 100644
--- a/sqle/server/auditplan/task_wrap.go
+++ b/sqle/server/auditplan/task_wrap.go
@@ -101,6 +101,7 @@ type TaskWrapper struct {
 	sync.WaitGroup
 	isStarted    bool
 	cancel       chan struct{}
+	cancelOnce   sync.Once
 	loopInterval func() time.Duration
 }
 
@@ -219,7 +220,11 @@ func (at *TaskWrapper) stopCollect() error {
 	if !at.isStarted {
 		return nil
 	}
-	at.cancel <- struct{}{}
+	// S2 scheme B: close once so Stop is non-blocking while ExtractSQL is still running.
+	// loop's `select { case <-cancel: }` unblocks on close; avoid unbuffered send deadlock.
+	at.cancelOnce.Do(func() {
+		close(at.cancel)
+	})
 	at.isStarted = false
 	at.WaitGroup.Wait()
 	at.logger.Infof("stop task")