diff --git a/libs/portal/shared/ui/src/lib/components/unified-collection/unified-live-tab.component.ts b/libs/portal/shared/ui/src/lib/components/unified-collection/unified-live-tab.component.ts
index a84606938..677c90f73 100644
--- a/libs/portal/shared/ui/src/lib/components/unified-collection/unified-live-tab.component.ts
+++ b/libs/portal/shared/ui/src/lib/components/unified-collection/unified-live-tab.component.ts
@@ -591,6 +591,12 @@ export class UnifiedLiveTabComponent {
         this.activeDetail.set(null);
         this.activeTimeshift.set(null);
         this.isSelecting.set(true);
+        // A previously owned radio override must not survive into a
+        // selection that never mounts a player surface of its own — external
+        // video playback and failed resolutions would otherwise keep the old
+        // radio credentials installed for that origin.
+        this.streamHeaders.clear(this.radioHeaderScopeUrl);
+        this.radioHeaderScopeUrl = null;
 
         try {
             const detail =
diff --git a/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.spec.ts b/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.spec.ts
index 259726302..5f53d3eb7 100644
--- a/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.spec.ts
+++ b/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.spec.ts
@@ -1214,6 +1214,35 @@ describe('StalkerLiveStreamLayoutComponent', () => {
         );
         expect(component.activePlayback()).toBeNull();
     });
+
+    it('releases the radio override when the next selection never mounts a player', async () => {
+        // Switching from a playing radio to a channel whose resolution fails
+        // (or plays externally) mounts no player surface — the selection
+        // itself must release the previously installed credentials.
+        stalkerStore.selectedContentType.set('radio');
+        selectedCategoryId.set('radio-all');
+        selectedItem.set(null);
+        selectedItvId.set(undefined);
+        fixture.detectChanges();
+        resolveRadioPlayback.mockResolvedValue({
+            streamUrl: 'http://portal.example/radio_2.mpg',
+            title: 'Portal FM',
+            headers: { Cookie: 'mac=00:1A:79:00:00:01' },
+        });
+        await component.playChannel(radioChannels()[0]);
+        await fixture.whenStable();
+
+        stalkerStore.selectedContentType.set('itv');
+        resolveItvPlayback.mockRejectedValueOnce(new Error('portal down'));
+        await component.playChannel(itvChannels()[0]);
+        await fixture.whenStable();
+
+        expect(window.electron?.setUserAgent).toHaveBeenLastCalledWith(
+            undefined,
+            undefined,
+            'http://portal.example/radio_2.mpg'
+        );
+    });
 });
 
 function buildProgram(channelId: string, title: string): EpgProgram {
diff --git a/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.ts b/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.ts
index a2f0c470f..56af7e4da 100644
--- a/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.ts
+++ b/libs/portal/stalker/feature/src/lib/stalker-live-stream-layout/stalker-live-stream-layout.component.ts
@@ -582,6 +582,12 @@ export class StalkerLiveStreamLayoutComponent implements OnDestroy {
         const channelId = normalizeStalkerEntityId(item.id);
         this.stalkerStore.setSelectedItem(item);
         this.ensureChannelWithinRenderWindow(channelId);
+        // A previously owned radio override must not survive into a
+        // selection that never mounts a player surface of its own — external
+        // video playback and failed resolutions would otherwise keep the old
+        // radio credentials installed for that origin.
+        this.streamHeaders.clear(this.radioHeaderScopeUrl);
+        this.radioHeaderScopeUrl = null;
 
         try {
             const isRadioMode = this.isRadioMode();