diff --git a/packages/views/issues/components/workspace-agent-working-chip.test.tsx b/packages/views/issues/components/workspace-agent-working-chip.test.tsx
new file mode 100644
index 000000000..036cbe023
--- /dev/null
+++ b/packages/views/issues/components/workspace-agent-working-chip.test.tsx
@@ -0,0 +1,149 @@
+// @vitest-environment jsdom
+
+import { cleanup, screen } from "@testing-library/react";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { AgentTask } from "@multica/core/types";
+import { renderWithI18n } from "../../test/i18n";
+
+const mockState = vi.hoisted(() => ({
+  snapshot: [] as unknown[],
+  // Captures the agent ids handed to the avatar stack so a test can assert
+  // the stack still reflects distinct agents even when the count counts issues.
+  avatarAgentIds: undefined as string[] | undefined,
+}));
+
+vi.mock("@multica/core/hooks", () => ({
+  useWorkspaceId: () => "ws-1",
+}));
+
+vi.mock("@multica/core/agents", () => ({
+  agentTaskSnapshotOptions: (wsId: string) => ({
+    queryKey: ["agents", "task-snapshot", wsId],
+  }),
+}));
+
+vi.mock("../../agents/components/agent-avatar-stack", () => ({
+  AgentAvatarStack: ({ agentIds }: { agentIds: string[] }) => {
+    mockState.avatarAgentIds = agentIds;
+    return <div data-testid="agent-avatar-stack">{agentIds.length}</div>;
+  },
+}));
+
+vi.mock("../../agents/components/agent-activity-hover-content", () => ({
+  AgentActivityHoverContent: ({ tasks }: { tasks: AgentTask[] }) => (
+    <div data-testid="activity-hover">{tasks.length}</div>
+  ),
+}));
+
+vi.mock("@tanstack/react-query", async () => {
+  const actual =
+    await vi.importActual<typeof import("@tanstack/react-query")>(
+      "@tanstack/react-query",
+    );
+  return {
+    ...actual,
+    useQuery: (opts: { queryKey?: readonly unknown[] }) => {
+      if (opts.queryKey?.[1] === "task-snapshot") {
+        return { data: mockState.snapshot };
+      }
+      return { data: undefined };
+    },
+  };
+});
+
+import { WorkspaceAgentWorkingChip } from "./workspace-agent-working-chip";
+
+function makeTask(overrides: Partial<AgentTask>): AgentTask {
+  return {
+    id: "task-1",
+    agent_id: "agent-1",
+    runtime_id: "runtime-1",
+    issue_id: "issue-1",
+    status: "running",
+    priority: 0,
+    dispatched_at: null,
+    started_at: "2026-06-08T08:00:00Z",
+    completed_at: null,
+    result: null,
+    error: null,
+    created_at: "2026-06-08T08:00:00Z",
+    ...overrides,
+  };
+}
+
+beforeEach(() => {
+  cleanup();
+  vi.clearAllMocks();
+  mockState.snapshot = [];
+  mockState.avatarAgentIds = undefined;
+});
+
+describe("WorkspaceAgentWorkingChip", () => {
+  it("counts distinct active issues, not running agents", () => {
+    // Two agents working the SAME issue: the count is about issues, so it
+    // must read "1", not "2" (the old unique-agent behavior). MUL-3875.
+    mockState.snapshot = [
+      makeTask({ id: "t-1", agent_id: "agent-1", issue_id: "issue-1" }),
+      makeTask({ id: "t-2", agent_id: "agent-2", issue_id: "issue-1" }),
+    ];
+
+    renderWithI18n(
+      <WorkspaceAgentWorkingChip value={false} onToggle={() => {}} />,
+    );
+
+    expect(
+      screen.getByRole("button", { name: /working/i }),
+    ).toHaveTextContent("1");
+    // The avatar stack still shows both distinct agents behind that work.
+    expect(mockState.avatarAgentIds).toEqual(["agent-1", "agent-2"]);
+  });
+
+  it("counts each distinct issue once when agents span several issues", () => {
+    mockState.snapshot = [
+      makeTask({ id: "t-1", agent_id: "agent-1", issue_id: "issue-1" }),
+      makeTask({ id: "t-2", agent_id: "agent-2", issue_id: "issue-2" }),
+      makeTask({ id: "t-3", agent_id: "agent-1", issue_id: "issue-3" }),
+    ];
+
+    renderWithI18n(
+      <WorkspaceAgentWorkingChip value={false} onToggle={() => {}} />,
+    );
+
+    expect(
+      screen.getByRole("button", { name: /working/i }),
+    ).toHaveTextContent("3");
+  });
+
+  it("ignores non-running tasks and respects scopedIssueIds", () => {
+    mockState.snapshot = [
+      makeTask({ id: "t-1", issue_id: "issue-1", status: "running" }),
+      makeTask({ id: "t-2", issue_id: "issue-2", status: "queued" }),
+      makeTask({ id: "t-3", issue_id: "issue-3", status: "running" }),
+    ];
+
+    renderWithI18n(
+      <WorkspaceAgentWorkingChip
+        value={false}
+        onToggle={() => {}}
+        scopedIssueIds={new Set(["issue-1"])}
+      />,
+    );
+
+    // Only the running task within scope counts → "1".
+    expect(
+      screen.getByRole("button", { name: /working/i }),
+    ).toHaveTextContent("1");
+  });
+
+  it("shows 0 when no agents are running", () => {
+    mockState.snapshot = [];
+
+    renderWithI18n(
+      <WorkspaceAgentWorkingChip value={false} onToggle={() => {}} />,
+    );
+
+    expect(
+      screen.getByRole("button", { name: /working/i }),
+    ).toHaveTextContent("0");
+  });
+});
diff --git a/packages/views/issues/components/workspace-agent-working-chip.tsx b/packages/views/issues/components/workspace-agent-working-chip.tsx
index 2ffe82772..e9b1a8573 100644
--- a/packages/views/issues/components/workspace-agent-working-chip.tsx
+++ b/packages/views/issues/components/workspace-agent-working-chip.tsx
@@ -65,7 +65,7 @@ export function WorkspaceAgentWorkingChip({
   const wsId = useWorkspaceId();
   const { data: snapshot = [] } = useQuery(agentTaskSnapshotOptions(wsId));
 
-  const { runningTasks, agentIds } = useMemo(() => {
+  const { runningTasks, agentIds, issueIds } = useMemo(() => {
     const running: AgentTask[] = [];
     for (const task of snapshot) {
       if (task.status !== "running") continue;
@@ -75,11 +75,21 @@ export function WorkspaceAgentWorkingChip({
       if (scopedIssueIds && !scopedIssueIds.has(task.issue_id)) continue;
       running.push(task);
     }
-    const unique = [...new Set(running.map((tk) => tk.agent_id))];
-    return { runningTasks: running, agentIds: unique };
+    // The count tracks active *issues*, not active agents: several agents
+    // can work the same issue at once, and the chip answers "how many
+    // issues are agents working on right now?" (its filter narrows the
+    // list to exactly those issues). The avatar stack still shows the
+    // distinct agents behind that work.
+    const uniqueIssues = [...new Set(running.map((tk) => tk.issue_id))];
+    const uniqueAgents = [...new Set(running.map((tk) => tk.agent_id))];
+    return {
+      runningTasks: running,
+      agentIds: uniqueAgents,
+      issueIds: uniqueIssues,
+    };
   }, [snapshot, scopedIssueIds]);
 
-  const hasAgents = agentIds.length > 0;
+  const hasAgents = issueIds.length > 0;
   // Active (brand-filled) class — must explicitly re-pin text and bg in
   // every interactive state. Button's `outline` variant ships
   // `hover:text-foreground` + `aria-expanded:bg-muted aria-expanded:text-foreground`,
@@ -140,7 +150,7 @@ export function WorkspaceAgentWorkingChip({
               max={3}
               opacity="full"
             />
-            <span className="tabular-nums">{agentIds.length}</span>
+            <span className="tabular-nums">{issueIds.length}</span>
             <span className="hidden md:inline">{label}</span>
           </Button>
         }