diff --git a/frontend/src/features/agents/CustomAgentChatView.test.tsx b/frontend/src/features/agents/CustomAgentChatView.test.tsx
index dce09046..458e7190 100644
--- a/frontend/src/features/agents/CustomAgentChatView.test.tsx
+++ b/frontend/src/features/agents/CustomAgentChatView.test.tsx
@@ -1764,6 +1764,118 @@ describe("CustomAgentChatView", () => {
     expect(screen.getAllByTestId("chat-tool-progress")).toHaveLength(2);
   });
 
+  it("keeps second-turn progress visible when the provider reuses the same progressId across turns", async () => {
+    const harness = createStreamingAgentHarness();
+
+    render(
+      <DIProvider
+        gateways={{
+          agent: harness.agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={vi.fn()}
+          onConversationId={vi.fn()}
+        />
+      </DIProvider>,
+    );
+
+    await waitFor(() =>
+      expect(harness.agent.reattachAgentChat).toHaveBeenCalledWith(
+        "chat-session-1",
+        expect.any(Function),
+      ),
+    );
+
+    fireEvent.change(screen.getByLabelText(/message CLI custom/), {
+      target: { value: "first request" },
+    });
+    fireEvent.click(screen.getByRole("button", { name: "Envoyer" }));
+    await waitFor(() => expect(harness.emitterCount()).toBe(1));
+
+    act(() => {
+      harness.emit(0, {
+        kind: "progress",
+        progress: {
+          progressId: "codex:item:call_1",
+          source: "providerNative",
+          kind: "tool",
+          stage: "started",
+          label: "shell",
+          toolName: "shell",
+          text: "Running first request",
+        },
+      });
+      harness.emit(0, {
+        kind: "progress",
+        progress: {
+          progressId: "codex:item:call_1",
+          source: "providerNative",
+          kind: "tool",
+          stage: "completed",
+          label: "shell",
+          toolName: "shell",
+          text: "Done first request",
+        },
+      });
+      harness.emit(0, { kind: "final", content: "done first request" });
+    });
+    await screen.findByText("done first request");
+
+    fireEvent.change(screen.getByLabelText(/message CLI custom/), {
+      target: { value: "second request" },
+    });
+    fireEvent.click(screen.getByRole("button", { name: "Envoyer" }));
+    await waitFor(() => expect(harness.emitterCount()).toBe(2));
+
+    act(() => {
+      harness.emit(1, {
+        kind: "progress",
+        progress: {
+          progressId: "codex:item:call_1",
+          source: "providerNative",
+          kind: "tool",
+          stage: "started",
+          label: "shell",
+          toolName: "shell",
+          text: "Running second request",
+        },
+      });
+    });
+
+    expect(screen.getByText("Running second request")).toBeTruthy();
+
+    act(() => {
+      harness.emit(1, {
+        kind: "progress",
+        progress: {
+          progressId: "codex:item:call_1",
+          source: "providerNative",
+          kind: "tool",
+          stage: "completed",
+          label: "shell",
+          toolName: "shell",
+          text: "Done second request",
+        },
+      });
+      harness.emit(1, { kind: "final", content: "done second request" });
+    });
+
+    await screen.findByText("done second request");
+    expect(screen.getByText("Done first request")).toBeTruthy();
+    expect(screen.getByText("Done second request")).toBeTruthy();
+    expect(screen.getAllByTestId("chat-tool-progress")).toHaveLength(2);
+  });
+
   it("ignores a late first-turn progress chunk but still shows the real second-turn progress from the next callback", async () => {
     const harness = createStreamingAgentHarness();
 
diff --git a/frontend/src/features/agents/CustomAgentChatView.tsx b/frontend/src/features/agents/CustomAgentChatView.tsx
index dc80bb9d..c7a0529b 100644
--- a/frontend/src/features/agents/CustomAgentChatView.tsx
+++ b/frontend/src/features/agents/CustomAgentChatView.tsx
@@ -325,7 +325,7 @@ function progressKey(progress: ReplyProgress): string {
 
 function progressUpsertKey(progress: ReplyProgress, scope: number): string {
   const progressId = progress.progressId?.trim();
-  if (progressId) return progressId;
+  if (progressId) return `progress:${scope}:${progressId}`;
   return `legacy:${scope}:${progressDisplayKey(progress)}`;
 }