diff --git a/packages/api/src/router/assistant.ts b/packages/api/src/router/assistant.ts
index 1cc2adfcb..3761e165f 100644
--- a/packages/api/src/router/assistant.ts
+++ b/packages/api/src/router/assistant.ts
@@ -271,6 +271,8 @@ export const assistantRouter = createTRPCRouter({
       const existing = await getConfigurationAsync(ctx.db);
       const destinationChanged =
         existing !== undefined && (existing.provider !== input.provider || existing.baseUrl !== baseUrl);
+      const connectionChanged =
+        existing !== undefined && (destinationChanged || existing.modelDiscoveryPath !== modelDiscoveryPath);
       const encryptedApiKey = input.apiKey
         ? encryptSecret(input.apiKey)
         : input.clearApiKey || destinationChanged
@@ -291,8 +293,8 @@ export const assistantRouter = createTRPCRouter({
             modelDiscoveryPath,
             encryptedApiKey,
             encryptedHeaders,
-            modelId: destinationChanged ? null : existing.modelId,
-            enabled: destinationChanged ? false : existing.enabled,
+            modelId: connectionChanged ? null : existing.modelId,
+            enabled: connectionChanged ? false : existing.enabled,
             updatedAt: new Date(),
           })
           .where(eq(assistantConfigurations.id, configurationId));
diff --git a/packages/api/src/router/test/assistant.spec.ts b/packages/api/src/router/test/assistant.spec.ts
new file mode 100644
index 000000000..214dece02
--- /dev/null
+++ b/packages/api/src/router/test/assistant.spec.ts
@@ -0,0 +1,92 @@
+// @vitest-environment node
+
+import { describe, expect, test, vi } from "vitest";
+
+import type { Session } from "@homarr/auth";
+import { createId } from "@homarr/common";
+import { assistantConfigurations } from "@homarr/db/schema";
+import { createDb } from "@homarr/db/test";
+
+import { assistantRouter } from "../assistant";
+
+vi.mock("@homarr/auth", () => ({}));
+vi.mock("@homarr/common/server", () => ({
+  decryptSecret: vi.fn(),
+  encryptSecret: vi.fn(),
+}));
+vi.mock("@homarr/core/infrastructure/logs", () => ({
+  createLogger: () => ({
+    error: vi.fn(),
+  }),
+}));
+vi.mock("@homarr/core/infrastructure/db/env", () => ({
+  dbEnv: { DRIVER: "better-sqlite3" },
+}));
+
+const adminSession = {
+  user: {
+    id: createId(),
+    permissions: ["admin"],
+    colorScheme: "light",
+  },
+  expires: new Date().toISOString(),
+} satisfies Session;
+
+const createConfiguredAssistantAsync = async () => {
+  const db = createDb();
+  await db.insert(assistantConfigurations).values({
+    id: "default",
+    enabled: true,
+    provider: "openrouter",
+    baseUrl: "https://openrouter.ai/api/v1",
+    modelDiscoveryPath: "/models",
+    encryptedApiKey: "encrypted.key",
+    encryptedHeaders: "encrypted.headers",
+    modelId: "example/model",
+  });
+  return db;
+};
+
+describe("assistantRouter.updateConnection", () => {
+  test("clears the persisted model when the discovery path changes without clearing credentials", async () => {
+    const db = await createConfiguredAssistantAsync();
+    const caller = assistantRouter.createCaller({ db, deviceType: undefined, session: adminSession });
+
+    await caller.updateConnection({
+      provider: "openrouter",
+      baseUrl: "https://openrouter.ai/api/v1",
+      modelDiscoveryPath: "/catalog",
+      clearApiKey: false,
+      clearCustomHeaders: false,
+    });
+
+    const [configuration] = await db.select().from(assistantConfigurations);
+    expect(configuration).toMatchObject({
+      enabled: false,
+      modelDiscoveryPath: "/catalog",
+      modelId: null,
+      encryptedApiKey: "encrypted.key",
+      encryptedHeaders: "encrypted.headers",
+    });
+  });
+
+  test("preserves the persisted model when the saved connection is unchanged", async () => {
+    const db = await createConfiguredAssistantAsync();
+    const caller = assistantRouter.createCaller({ db, deviceType: undefined, session: adminSession });
+
+    await caller.updateConnection({
+      provider: "openrouter",
+      baseUrl: "https://openrouter.ai/api/v1",
+      modelDiscoveryPath: "/models",
+      clearApiKey: false,
+      clearCustomHeaders: false,
+    });
+
+    const [configuration] = await db.select().from(assistantConfigurations);
+    expect(configuration).toMatchObject({
+      enabled: true,
+      modelDiscoveryPath: "/models",
+      modelId: "example/model",
+    });
+  });
+});