fix

Author: Gorash

packages/plugin-dom-layout/src/DomLayoutEngine.ts

@@ -140,9 +140,13 @@ export class DomLayoutEngine extends LayoutEngine {
 
         // Render nodes.
         const renderer = this.editor.plugins.get(Renderer);
-        const domObjects = (await renderer.render<DomObject>('dom/object', nodes)) || [];
+        let domObjects = (await renderer.render<DomObject>('dom/object', nodes)) || [];
         const engine = renderer.engines['dom/object'] as DomObjectRenderingEngine;
 
+        domObjects = domObjects.filter(
+            (domObject, index) => domObjects.indexOf(domObject) === index,
+        );
+
         this._domReconciliationEngine.update(
             domObjects,
             engine.locations,