diff --git a/public/app/fn-app/fn-dashboard-page/fn-dashboard.test.tsx b/public/app/fn-app/fn-dashboard-page/fn-dashboard.test.tsx
index b8253d2a78cc7..813abf554490c 100644
--- a/public/app/fn-app/fn-dashboard-page/fn-dashboard.test.tsx
+++ b/public/app/fn-app/fn-dashboard-page/fn-dashboard.test.tsx
@@ -106,8 +106,10 @@ describe('FNDashboard', () => {
   afterEach(() => {
     cleanup();
     act(() => {
-      for (const uid of dashboardUIDs) {
+      for (const uid of Object.keys(mfeGetStoreState().fnGlobalReducer.dashboards)) {
         mfeDispatch(removeGrafanaStoreAndDashboard(uid));
+      }
+      for (const uid of dashboardUIDs) {
         document.getElementById(`${uid}-portal`)?.remove();
       }
       mfeDispatch(updateRenderingDashboardUID(''));
@@ -140,6 +142,50 @@ describe('FNDashboard', () => {
     expect(consoleError.mock.calls.flat().join(' ')).not.toContain('Cannot update a component');
   });
 
+  it('replaces the dashboard owning a stable portal through draft creation and save', () => {
+    const publishedUid = dashboardUIDs[0];
+    const draftUid = 'custom-dashboard-draft';
+    const portalContainerID = `${publishedUid}-portal`;
+    render(
+      <FNDashboard
+        name="dashboard"
+        isLoading={jest.fn()}
+        pageTitle="Dashboard"
+        setErrors={jest.fn()}
+        metadata={{ teams: [], eventListener: null }}
+        fnError={null}
+      />
+    );
+
+    for (const uid of [draftUid, publishedUid, draftUid, publishedUid]) {
+      const previousUid = uid === draftUid ? publishedUid : draftUid;
+      act(() => mfeDispatch(updatePartialMfeStates({ uid, portalContainerID })));
+
+      expect(document.getElementById(portalContainerID)!.querySelectorAll('.page-dashboard')).toHaveLength(1);
+      expect(screen.getByTestId(`dashboard-${uid}`)).toBeInTheDocument();
+      expect(screen.queryByTestId(`dashboard-${previousUid}`)).not.toBeInTheDocument();
+      expect(mfeGetStoreState().fnGlobalReducer.grafanaStores[previousUid]).toBeUndefined();
+      expect(mfeGetStoreState().fnGlobalReducer.renderingDashboardUID).toBe(uid);
+    }
+  });
+
+  it('preserves the existing store on same-UID updates and unrelated portals on replacement', () => {
+    mountDashboard(dashboardUIDs[1]);
+    const parentStore = mfeGetStoreState().fnGlobalReducer.grafanaStores[dashboardUIDs[0]];
+    const drawerStore = mfeGetStoreState().fnGlobalReducer.grafanaStores[dashboardUIDs[1]];
+    mfeDispatch(updatePartialMfeStates({ uid: dashboardUIDs[0], refreshRevision: 3 }));
+    mfeDispatch(updatePartialMfeStates({ uid: dashboardUIDs[0], portalContainerID: `${dashboardUIDs[0]}-portal` }));
+    expect(mfeGetStoreState().fnGlobalReducer.grafanaStores[dashboardUIDs[0]]).toBe(parentStore);
+    expect(mfeGetStoreState().fnGlobalReducer.dashboards[dashboardUIDs[0]].refreshRevision).toBe(3);
+
+    mfeDispatch(updatePartialMfeStates({ uid: 'draft', portalContainerID: `${dashboardUIDs[0]}-portal` }));
+    expect(mfeGetStoreState().fnGlobalReducer.grafanaStores[dashboardUIDs[1]]).toBe(drawerStore);
+    expect(mfeGetStoreState().fnGlobalReducer.dashboards[dashboardUIDs[1]].portalContainerID).toBe(
+      `${dashboardUIDs[1]}-portal`
+    );
+    expect(mfeGetStoreState().fnGlobalReducer.grafanaStores[dashboardUIDs[0]]).toBeUndefined();
+  });
+
   it('restores the preserved parent time owner after drawer removal without refreshing it', () => {
     const parent = makeModel();
     mfeGetStoreState().fnGlobalReducer.grafanaStores[dashboardUIDs[0]].dispatch({ type: 'test/model', model: parent });
diff --git a/public/app/store/configureMfeStore.ts b/public/app/store/configureMfeStore.ts
index 476270149e1a9..993b9ee9931d0 100644
--- a/public/app/store/configureMfeStore.ts
+++ b/public/app/store/configureMfeStore.ts
@@ -50,6 +50,19 @@ function setGrafanaStore(state: WritableDraft<MfeGlobalState>, uid: string, init
 const reducers: SliceCaseReducers<MfeGlobalState> = {
   updatePartialMfeStates: (state, action: UpdateFNGlobalStateAction) => {
     const { uid, ...partialState } = action.payload;
+    // A host portal has one dashboard owner. Custom dashboards keep the DOM
+    // container while switching between published and draft UIDs; retaining
+    // both stores would render both dashboards into that same container.
+    // Only explicit container updates transfer ownership, not async refresh
+    // completions or other UID-only state patches.
+    if (uid && partialState.portalContainerID) {
+      for (const [previousUid, dashboard] of Object.entries(state.dashboards)) {
+        if (previousUid !== uid && dashboard.portalContainerID === partialState.portalContainerID) {
+          delete state.dashboards[previousUid];
+          delete state.grafanaStores[previousUid];
+        }
+      }
+    }
     setGrafanaStore(state, uid, partialState);
     const fnState = state.dashboards[uid];
     state.FNDashboard = true;