diff --git a/src/db/repositories.ts b/src/db/repositories.ts
index 7bcf60859b..9ddb3d6529 100644
--- a/src/db/repositories.ts
+++ b/src/db/repositories.ts
@@ -377,16 +377,25 @@ function resolveLinkedIssueClaimedAt(
 ): string | null {
   if (linkedIssues.length === 0) return null;
   if (!existing) return observedLinkedIssueClaimedAt;
-  if (existing.linkedIssuesJson === linkedIssuesJson) return existing.linkedIssueClaimedAt ?? observedLinkedIssueClaimedAt;
-  if (existing.linkedIssueClaimedAt && linkedIssuesOverlap(parseJson<number[]>(existing.linkedIssuesJson, []), linkedIssues)) {
-    return existing.linkedIssueClaimedAt;
-  }
+  if (
+    existing.linkedIssuesJson === linkedIssuesJson ||
+    sameLinkedIssueSet(parseLinkedIssuesJson(existing.linkedIssuesJson), linkedIssues)
+  )
+    return existing.linkedIssueClaimedAt ?? observedLinkedIssueClaimedAt;
   return observedLinkedIssueClaimedAt;
 }
 
-function linkedIssuesOverlap(left: number[], right: number[]): boolean {
-  const rightIssues = new Set(right);
-  return left.some((issue) => rightIssues.has(issue));
+function parseLinkedIssuesJson(value: string): number[] {
+  const parsed = parseJson<unknown>(value, []);
+  return Array.isArray(parsed) ? (parsed as number[]) : [];
+}
+
+function sameLinkedIssueSet(left: number[], right: number[]): boolean {
+  return normalizedLinkedIssueSet(left) === normalizedLinkedIssueSet(right);
+}
+
+function normalizedLinkedIssueSet(numbers: number[]): string {
+  return jsonString([...new Set(numbers)].sort((left, right) => left - right));
 }
 
 export async function upsertIssueFromGitHub(env: Env, repoFullName: string, issue: GitHubIssuePayload, options: { seenOpenAt?: string } = {}): Promise<IssueRecord> {
diff --git a/test/unit/db-parsers.test.ts b/test/unit/db-parsers.test.ts
index 1faf0a52df..b1bd5d7192 100644
--- a/test/unit/db-parsers.test.ts
+++ b/test/unit/db-parsers.test.ts
@@ -92,7 +92,7 @@ describe("database row parser hardening", () => {
     );
   });
 
-  it("REGRESSION: adding another linked issue preserves the original shared-issue claim time", async () => {
+  it("REGRESSION: adding another linked issue resets the PR-level claim time", async () => {
     const env = createTestEnv();
 
     vi.useFakeTimers();
@@ -136,7 +136,23 @@ describe("database row parser hardening", () => {
     expect(expanded).toMatchObject({
       title: "Expanded claim",
       linkedIssues: [1, 2],
-      linkedIssueClaimedAt: first?.linkedIssueClaimedAt,
+      linkedIssueClaimedAt: "2026-06-29T10:05:00.000Z",
+    });
+
+    vi.setSystemTime(new Date("2026-06-29T10:07:00.000Z"));
+    await upsertPullRequestFromGitHub(env, "owner/repo", {
+      number: 11,
+      title: "Reordered expanded claim",
+      state: "open",
+      user: { login: "alice" },
+      labels: [],
+      body: "Fixes #2\nFixes #1",
+    });
+    const reordered = (await listPullRequests(env, "owner/repo")).find((p) => p.number === 11);
+    expect(reordered).toMatchObject({
+      title: "Reordered expanded claim",
+      linkedIssues: [2, 1],
+      linkedIssueClaimedAt: expanded?.linkedIssueClaimedAt,
     });
 
     vi.setSystemTime(new Date("2026-06-29T10:10:00.000Z"));
@@ -203,6 +219,41 @@ describe("database row parser hardening", () => {
     });
   });
 
+  it("repairs sparse non-array linked issue cache rows without throwing", async () => {
+    const env = createTestEnv();
+
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-06-29T11:10:00.000Z"));
+    await upsertPullRequestFromGitHub(env, "owner/repo", {
+      number: 13,
+      title: "Sparse cached claim",
+      state: "open",
+      user: { login: "alice" },
+      labels: [],
+      body: "Fixes #8",
+    });
+    await env.DB.prepare("UPDATE pull_requests SET linked_issues_json = ? WHERE repo_full_name = ? AND number = ?")
+      .bind("{}", "owner/repo", 13)
+      .run();
+
+    vi.setSystemTime(new Date("2026-06-29T11:12:00.000Z"));
+    await upsertPullRequestFromGitHub(env, "owner/repo", {
+      number: 13,
+      title: "Sparse cached claim repaired",
+      state: "open",
+      user: { login: "alice" },
+      labels: [],
+      body: "Fixes #8",
+    });
+
+    const repaired = (await listPullRequests(env, "owner/repo")).find((p) => p.number === 13);
+    expect(repaired).toMatchObject({
+      title: "Sparse cached claim repaired",
+      linkedIssues: [8],
+      linkedIssueClaimedAt: "2026-06-29T11:12:00.000Z",
+    });
+  });
+
   it("markPullRequestRegated stamps the internal last_regated_at marker (sweep convergence #audit-sweep-converge)", async () => {
     const env = createTestEnv();
     await upsertPullRequestFromGitHub(env, "owner/repo", { number: 5, title: "Stale PR", state: "open", user: { login: "alice" }, labels: [] });