diff --git a/ui/web/src/pages/channels/channel-detail/channel-detail-page.tsx b/ui/web/src/pages/channels/channel-detail/channel-detail-page.tsx
index 895e8149..dce2aa1c 100644
--- a/ui/web/src/pages/channels/channel-detail/channel-detail-page.tsx
+++ b/ui/web/src/pages/channels/channel-detail/channel-detail-page.tsx
@@ -21,6 +21,7 @@ import {
   getChannelRemediationMeta,
   getRenderableChannelStatus,
   getChannelStatusMeta,
+  shouldShowChannelDiagnosticsCard,
 } from "../channels-status-view";
 import { useChannelTimeline } from "./channel-detail-timeline-hook";
 import { ChannelDetailDialogs } from "./channel-detail-dialogs";
@@ -139,12 +140,7 @@ export function ChannelDetailPage({
 
   const timelineItems = useChannelTimeline(status, t);
 
-  const showDiagnosticsCard =
-    status?.state === "failed" ||
-    status?.state === "degraded" ||
-    !!status?.remediation ||
-    !!status?.consecutive_failures ||
-    !!status?.first_failed_at;
+  const showDiagnosticsCard = shouldShowChannelDiagnosticsCard(status);
 
   const neutralHealthNote =
     !showDiagnosticsCard &&
diff --git a/ui/web/src/pages/channels/channels-status-utils.test.ts b/ui/web/src/pages/channels/channels-status-utils.test.ts
new file mode 100644
index 00000000..b6c0290f
--- /dev/null
+++ b/ui/web/src/pages/channels/channels-status-utils.test.ts
@@ -0,0 +1,35 @@
+import { describe, expect, it } from "vitest";
+import type { ChannelRuntimeStatus } from "@/types/channel";
+import { shouldShowChannelDiagnosticsCard } from "./channels-status-utils";
+
+function status(overrides: Partial<ChannelRuntimeStatus>): ChannelRuntimeStatus {
+  return {
+    enabled: true,
+    running: true,
+    state: "healthy",
+    ...overrides,
+  };
+}
+
+describe("shouldShowChannelDiagnosticsCard", () => {
+  it("ignores Go zero-value first_failed_at timestamps on healthy channels", () => {
+    expect(
+      shouldShowChannelDiagnosticsCard(
+        status({ first_failed_at: "0001-01-01T00:00:00Z" }),
+      ),
+    ).toBe(false);
+  });
+
+  it("shows diagnostics for meaningful failure timestamps", () => {
+    expect(
+      shouldShowChannelDiagnosticsCard(
+        status({ first_failed_at: "2026-01-01T00:00:00Z" }),
+      ),
+    ).toBe(true);
+  });
+
+  it("still shows diagnostics for active degraded or failed states", () => {
+    expect(shouldShowChannelDiagnosticsCard(status({ state: "degraded" }))).toBe(true);
+    expect(shouldShowChannelDiagnosticsCard(status({ state: "failed" }))).toBe(true);
+  });
+});
diff --git a/ui/web/src/pages/channels/channels-status-utils.ts b/ui/web/src/pages/channels/channels-status-utils.ts
index 12e9f958..70af4949 100644
--- a/ui/web/src/pages/channels/channels-status-utils.ts
+++ b/ui/web/src/pages/channels/channels-status-utils.ts
@@ -161,6 +161,18 @@ export function getChannelCheckedLabel(
   });
 }
 
+export function shouldShowChannelDiagnosticsCard(
+  status: ChannelRuntimeStatus | null | undefined,
+) {
+  return (
+    status?.state === "failed" ||
+    status?.state === "degraded" ||
+    !!status?.remediation ||
+    !!status?.consecutive_failures ||
+    !!formatRelativeTime(status?.first_failed_at)
+  );
+}
+
 export function getChannelFailureKindLabel(
   kind: ChannelRuntimeStatus["failure_kind"],
   t: TFunction,
diff --git a/ui/web/src/pages/channels/channels-status-view.tsx b/ui/web/src/pages/channels/channels-status-view.tsx
index 5b71220e..9a86de1f 100644
--- a/ui/web/src/pages/channels/channels-status-view.tsx
+++ b/ui/web/src/pages/channels/channels-status-view.tsx
@@ -23,6 +23,7 @@ export {
   getRenderableChannelStatus,
   getChannelCheckedLabel,
   getChannelFailureKindLabel,
+  shouldShowChannelDiagnosticsCard,
   getChannelAttentionPriority,
   getChannelStatusMeta,
   getChannelRemediationMeta,