diff --git a/src/chart/line/LineView.ts b/src/chart/line/LineView.ts
index 847a876495..7d9f4aca68 100644
--- a/src/chart/line/LineView.ts
+++ b/src/chart/line/LineView.ts
@@ -1037,6 +1037,11 @@ class LineView extends ChartView {
         // Remove previous created polyline
         if (polyline) {
             this._lineGroup.remove(polyline);
+            // endLabel is attached to the previous polyline, recreate it on the new one.
+            if (this._endLabel) {
+                polyline.removeTextContent();
+                this._endLabel = null;
+            }
         }
 
         polyline = new ECPolyline({
diff --git a/test/ut/spec/series/line.test.ts b/test/ut/spec/series/line.test.ts
new file mode 100644
index 0000000000..a601ca0391
--- /dev/null
+++ b/test/ut/spec/series/line.test.ts
@@ -0,0 +1,74 @@
+/*
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements.  See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership.  The ASF licenses this file
+* to you under the Apache License, Version 2.0 (the
+* "License"); you may not use this file except in compliance
+* with the License.  You may obtain a copy of the License at
+*
+*   http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing,
+* software distributed under the License is distributed on an
+* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+* KIND, either express or implied.  See the License for the
+* specific language governing permissions and limitations
+* under the License.
+*/
+
+import { createChart } from '../../core/utHelper';
+import { EChartsType } from '@/src/echarts';
+
+
+describe('line', function () {
+
+    function makeOption(step: 'end' | false) {
+        return {
+            animation: false,
+            xAxis: { type: 'value' },
+            yAxis: { type: 'value' },
+            series: [{
+                type: 'line',
+                name: 'A',
+                step,
+                data: [[0, 1], [1, 3], [2, 2]],
+                endLabel: { show: true, formatter: '{a}' }
+            }]
+        };
+    }
+
+    function getLineView(chart: EChartsType) {
+        const seriesModel = (chart as any).getModel().getSeriesByIndex(0);
+        return (chart as any).getViewOfSeriesModel(seriesModel);
+    }
+
+    function expectEndLabelAttached(chart: EChartsType) {
+        const view = getLineView(chart);
+        const endLabel = view._endLabel;
+        expect(!!endLabel).toBe(true);
+        // Compare by identity to avoid jest deep-printing graphic elements.
+        expect(view._polyline.getTextContent() === endLabel).toBe(true);
+        expect(endLabel.style.text).toBe('A');
+    }
+
+    // See #21833
+    it('should keep endLabel when step is changed by setOption', function () {
+        const chart = createChart({width: 400, height: 300});
+
+        try {
+            chart.setOption(makeOption('end'));
+            expectEndLabelAttached(chart);
+
+            chart.setOption(makeOption(false), { notMerge: true });
+            expectEndLabelAttached(chart);
+
+            chart.setOption(makeOption('end'));
+            expectEndLabelAttached(chart);
+        }
+        finally {
+            chart.dispose();
+        }
+    });
+
+});