diff --git a/src/lib/db/models/activeSyncedCatalog.ts b/src/lib/db/models/activeSyncedCatalog.ts
index 4e68a17d2b..9c34f685dd 100644
--- a/src/lib/db/models/activeSyncedCatalog.ts
+++ b/src/lib/db/models/activeSyncedCatalog.ts
@@ -184,10 +184,12 @@ async function unionCustomModels(
  */
 async function loadConnectionCatalog(storedProviderId: string): Promise<SyncedAvailableModel[]> {
   const [connections, modelsByConnection] = await Promise.all([
-    getRawProviderConnections({ provider: storedProviderId, isActive: true }, undefined, undefined, [
-      "id",
-      "provider",
-    ]),
+    getRawProviderConnections(
+      { provider: storedProviderId, isActive: true },
+      undefined,
+      undefined,
+      ["id", "provider"]
+    ),
     getSyncedAvailableModelsByConnection(storedProviderId),
   ]);
 
@@ -248,6 +250,18 @@ export async function getActiveSyncedCatalog(providerId: string): Promise<Active
 /**
  * Return non-empty synced catalogs grouped by provider, restricted to active
  * connections. This is the authoritative live source for /v1/models.
+ *
+ * Deliberately does NOT union `customModels` the way the dispatch-time readers
+ * above do (#12597). Its three consumers all read this as "what the provider's
+ * live sync reported": /v1/models emits synced rows through their own loop and
+ * has a separate custom-model pass right after it (with the specialty-registry
+ * dedupe, hidePaid and vision overrides that pass owns); /api/models uses it to
+ * decide whether an exclusive-listing provider's live catalog suppresses a static
+ * row; getSyncedAutoAliases derives tier aliases from it. Blurring operator custom
+ * rows into "synced" made /v1/models emit a custom specialty model under the
+ * provider's ALIAS as the parentless primary row (`jina/<id>`) and demote the
+ * embedding/rerank registry's canonical `jina-ai/<id>` to a child — the inverse of
+ * the identity every other specialty model of that provider carries.
  */
 export async function getAllActiveSyncedModels(): Promise<Record<string, SyncedAvailableModel[]>> {
   try {
@@ -277,10 +291,7 @@ export async function getAllActiveSyncedModels(): Promise<Record<string, SyncedA
 
         const models = enrichCursorCatalog(
           providerId,
-          await unionCustomModels(
-            providerId,
-            collectModelsForConnections(modelsByConnection, connectionIds)
-          )
+          collectModelsForConnections(modelsByConnection, connectionIds)
         );
 
         if (models.length > 0) {
diff --git a/tests/unit/custom-models-live-catalog-12597.test.ts b/tests/unit/custom-models-live-catalog-12597.test.ts
index 4e6bb35068..b81745aeb9 100644
--- a/tests/unit/custom-models-live-catalog-12597.test.ts
+++ b/tests/unit/custom-models-live-catalog-12597.test.ts
@@ -14,10 +14,14 @@ process.env.DATA_DIR = TEST_DATA_DIR;
 process.env.API_KEY_SECRET = process.env.API_KEY_SECRET || "custom-live-12597-test-secret";
 
 const core = await import("../../src/lib/db/core.ts");
-const { addCustomModel, replaceSyncedAvailableModelsForConnection, getActiveProvidersWithSyncedModel } =
-  await import("../../src/lib/db/models.ts");
+const {
+  addCustomModel,
+  replaceSyncedAvailableModelsForConnection,
+  getActiveProvidersWithSyncedModel,
+} = await import("../../src/lib/db/models.ts");
 const {
   getActiveSyncedCatalog,
+  getAllActiveSyncedModels,
   catalogContainsModel,
   reconcileProvidersWithActiveSyncedCatalog,
 } = await import("../../src/lib/db/models/activeSyncedCatalog.ts");
@@ -124,6 +128,21 @@ test("#12597 sparse custom overlay does not wipe synced capability fields", asyn
   assert.deepEqual(match?.supportedThinkingEfforts, ["low", "high"]);
 });
 
+test("#12597 the union is dispatch-only — getAllActiveSyncedModels stays live-sync-shaped", async () => {
+  await addCustomModel(PROVIDER, PICKER_MODEL, "DeepSeek R1 via picker");
+
+  const allActive = await getAllActiveSyncedModels();
+  const ids = (allActive[PROVIDER] ?? []).map((model) => model.id);
+
+  assert.deepEqual(
+    ids,
+    [SYNCED_MODEL],
+    "getAllActiveSyncedModels reports what the provider's live sync returned; its consumers (/v1/models' synced loop, /api/models' exclusive-listing suppression, getSyncedAutoAliases) each handle custom rows on their own"
+  );
+  // The dispatch-time readers still see it — that is what #12597 fixed.
+  assert.equal(catalogContainsModel(await getActiveSyncedCatalog(PROVIDER), PICKER_MODEL), true);
+});
+
 test("#12597 without a custom row the picker id is still absent (lock the old contract)", async () => {
   const catalog = await getActiveSyncedCatalog(PROVIDER);
   assert.equal(catalogContainsModel(catalog, PICKER_MODEL), false);