diff --git a/internal/topo/node/window_op.go b/internal/topo/node/window_op.go
index 9381c22d0..88d426c43 100644
--- a/internal/topo/node/window_op.go
+++ b/internal/topo/node/window_op.go
@@ -358,7 +358,8 @@ func (o *WindowOperator) execProcessingWindow(ctx api.StreamContext, inputs []*x
 						}
 					} else {
 						// clear inputs if condition not matched
-						inputs = o.gcInputs(inputs, d.Timestamp.Add(o.window.Delay), ctx)
+						// TS add 1 to prevent remove current input
+						inputs = o.gcInputs(inputs, d.Timestamp.Add(1), ctx)
 					}
 				case ast.SESSION_WINDOW:
 					if timeoutTicker != nil {
@@ -568,7 +569,7 @@ func (o *WindowOperator) handleInputs(ctx api.StreamContext, inputs []*xsql.Tupl
 	content := make([]xsql.Row, 0, len(inputs))
 	// Sync table
 	left := right.Add(-length).Add(-delta)
-	log.Debugf("triggerTime: %d, length: %d, delta: %d, leftmost: %d", left.UnixMilli(), length, delta, left.UnixMilli())
+	log.Debugf("triggerTime: %d, length: %d, delta: %d, leftmost: %d", right.UnixMilli(), length, delta, left.UnixMilli())
 	nextleft := -1
 	// Assume the inputs are sorted by timestamp
 	for i, tuple := range inputs {