diff --git a/dashcaddy-api/__tests__/network-people-store.test.js b/dashcaddy-api/__tests__/network-people-store.test.js
index 8d1c715..56079b9 100644
--- a/dashcaddy-api/__tests__/network-people-store.test.js
+++ b/dashcaddy-api/__tests__/network-people-store.test.js
@@ -82,6 +82,26 @@ describe('network-people-store: CRUD', () => {
     expect(list).toHaveLength(1); // merged, not duplicated
   });
 
+  test('upsertPerson merges by providerUserId when id is omitted (wizard after provider sync)', async () => {
+    const synced = await store.upsertPerson({
+      displayName: 'SamiAhmed7777',
+      providerUserId: 'ughVnuLDu621CNTRL',
+    });
+    expect(synced.groups).toEqual(['Admin']); // bootstrap identity
+
+    const fromWizard = await store.upsertPerson({
+      displayName: 'Sami Ahmed',
+      providerUserId: 'ughVnuLDu621CNTRL',
+    });
+
+    expect(fromWizard.id).toBe(synced.id);
+    expect(fromWizard.displayName).toBe('Sami Ahmed');
+    expect(fromWizard.groups).toEqual(['Admin']);
+    expect(fromWizard.protectedAt).toBe(synced.protectedAt);
+    const list = await store.listPeople();
+    expect(list).toHaveLength(1);
+  });
+
   test('updatePerson patches only provided fields', async () => {
     const p = await store.upsertPerson({ displayName: 'Bob', providerUserId: 'ts-2', groups: ['G'] });
     const u = await store.updatePerson(p.id, { displayName: 'Bobby' });
diff --git a/dashcaddy-api/src/security/network-people-store.js b/dashcaddy-api/src/security/network-people-store.js
index 71b9e6a..b9a028d 100644
--- a/dashcaddy-api/src/security/network-people-store.js
+++ b/dashcaddy-api/src/security/network-people-store.js
@@ -180,7 +180,17 @@ function createPeopleStore(opts = {}) {
   function upsertPerson(input = {}) {
     return _enqueue(() => {
       const data = _load();
-      const existing = input.id ? data.people[input.id] : null;
+      // Resolve the existing record by id when given, else by providerUserId
+      // (dogfood finding 2026-10-04: the wizard upserts a person AFTER a
+      // provider sync already created one for the same Tailscale user with no
+      // id — without this lookup the same providerUserId was duplicated).
+      const existing = input.id
+        ? data.people[input.id]
+        : (input.providerUserId
+            ? Object.values(data.people).find(
+                (p) => p.providerUserId && p.providerUserId === input.providerUserId
+              ) || null
+            : null);
       const isFirst = Object.keys(data.people).length === 0;
 
       const id = existing ? existing.id : (input.id || crypto.randomUUID());