diff --git a/src/agents/prepared-model-catalog.scoped-thinking.test.ts b/src/agents/prepared-model-catalog.scoped-thinking.test.ts
index aae855040ec7..db5d9e4c711b 100644
--- a/src/agents/prepared-model-catalog.scoped-thinking.test.ts
+++ b/src/agents/prepared-model-catalog.scoped-thinking.test.ts
@@ -1,6 +1,9 @@
 // Boundary proof for the turn-path thinking fallback: manifest first, then a provider-scoped
 // static catalog, then scoped live discovery only for runtime-only models (e.g. Ollama).
 import { beforeEach, describe, expect, it, vi } from "vitest";
+import { createPluginMetadataSnapshot } from "../config/plugin-auto-enable.test-helpers.js";
+import { PreparedModelRuntimeOwnerNotPublishedError } from "./prepared-model-runtime.errors.js";
+import type { PreparedModelRuntimeSnapshot } from "./prepared-model-runtime.types.js";
 
 const manifestCatalogMock = vi.fn((..._args: unknown[]): Array<Record<string, unknown>> => []);
 const scopedStaticMock = vi.fn(
@@ -16,6 +19,13 @@ const scopedLiveMock = vi.fn(
   }),
 );
 const publishedSnapshotMock = vi.fn((..._args: unknown[]) => undefined as unknown);
+const preparedSnapshotMock = vi.fn<
+  (input: { agentDir: string }) => Promise<PreparedModelRuntimeSnapshot>
+>(async (input) => {
+  throw new PreparedModelRuntimeOwnerNotPublishedError(
+    `not published for test (${input.agentDir})`,
+  );
+});
 
 vi.mock("./model-catalog.js", () => ({
   loadManifestModelCatalog: (...args: unknown[]) => manifestCatalogMock(...args),
@@ -27,11 +37,8 @@ vi.mock("./prepared-model-runtime.js", async (importOriginal) => {
     ...actual,
     getPreparedModelRuntimeSnapshot: (...args: unknown[]) => publishedSnapshotMock(...args),
     // No published lifecycle owner: force the scoped read-only builders to run.
-    prepareModelRuntimeSnapshot: vi.fn(async (input: { agentDir: string }) => {
-      throw new actual.PreparedModelRuntimeOwnerNotPublishedError(
-        `not published for test (${input.agentDir})`,
-      );
-    }),
+    prepareModelRuntimeSnapshot: (...args: Parameters<typeof preparedSnapshotMock>) =>
+      preparedSnapshotMock(...args),
   };
 });
 
@@ -54,6 +61,11 @@ describe("loadProviderScopedThinkingCatalog", () => {
     scopedStaticMock.mockResolvedValue({ entries: [], routeVariants: [] });
     scopedLiveMock.mockResolvedValue({ entries: [], routeVariants: [] });
     publishedSnapshotMock.mockReturnValue(undefined);
+    preparedSnapshotMock.mockImplementation(async (input) => {
+      throw new PreparedModelRuntimeOwnerNotPublishedError(
+        `not published for test (${input.agentDir})`,
+      );
+    });
   });
 
   it("prefers the published prepared generation over partial manifest compatibility", async () => {
@@ -130,6 +142,42 @@ describe("loadProviderScopedThinkingCatalog", () => {
     expect(scopedLiveMock).not.toHaveBeenCalled();
   });
 
+  it("falls back to the scoped catalog while a published owner has the replaced config", async () => {
+    preparedSnapshotMock.mockResolvedValue({
+      agentDir: "/tmp/model-catalog-test",
+      activeProjectKeys: [],
+      config: { skills: { entries: { marker: { enabled: false } } } },
+      authModes: {},
+      metadataSnapshot: createPluginMetadataSnapshot({
+        config: {},
+        manifestRegistry: { plugins: [], diagnostics: [] },
+      }),
+      allowGatewaySubagentBinding: false,
+      modelCatalog: { entries: [], routeVariants: [] },
+      configuredRuntimeModels: [],
+      inlineProviderModels: [],
+      createStores: () => {
+        throw new Error("stores are outside this catalog fallback test");
+      },
+    });
+    scopedStaticMock.mockResolvedValue({
+      entries: [{ provider: "acme", id: "replacement-model", reasoning: true }],
+      routeVariants: [],
+    });
+    const { loadProviderScopedThinkingCatalog } = await import("./prepared-model-catalog.js");
+
+    const catalog = await loadProviderScopedThinkingCatalog({
+      config: { skills: { entries: { marker: { enabled: true } } } },
+      provider: "acme",
+      model: "replacement-model",
+    });
+
+    expect(catalog).toEqual([
+      expect.objectContaining({ provider: "acme", id: "replacement-model", reasoning: true }),
+    ]);
+    expect(scopedStaticMock).toHaveBeenCalledWith(expect.anything(), ["acme"]);
+  });
+
   it("runs provider-scoped live discovery for runtime-only models and keeps their thinking", async () => {
     scopedLiveMock.mockResolvedValue({ entries: [ollamaEntry], routeVariants: [] });
     const { loadProviderScopedThinkingCatalog } = await import("./prepared-model-catalog.js");
diff --git a/src/agents/prepared-model-catalog.ts b/src/agents/prepared-model-catalog.ts
index fe5b89738027..4586ac8eb4bb 100644
--- a/src/agents/prepared-model-catalog.ts
+++ b/src/agents/prepared-model-catalog.ts
@@ -332,7 +332,7 @@ async function loadScopedReadOnlyModelCatalog(
     try {
       const prepared = await prepareModelRuntimeSnapshot(candidate);
       if (!preparedModelRuntimeConfigsMatch(prepared.config, candidate.config)) {
-        throw new PreparedModelCatalogConfigReplacedError(candidate.agentDir);
+        continue;
       }
       if (isPreparedModelCatalogFull(prepared.modelCatalog)) {
         return prepared.modelCatalog;