diff --git a/apps/desktop/src/app/settings/model-settings.test.tsx b/apps/desktop/src/app/settings/model-settings.test.tsx
index 3f81d238f..4ba6fd512 100644
--- a/apps/desktop/src/app/settings/model-settings.test.tsx
+++ b/apps/desktop/src/app/settings/model-settings.test.tsx
@@ -1,5 +1,5 @@
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import { cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { act, cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react'
 import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
 
 // Radix Select calls scrollIntoView on its items when the content opens; jsdom
@@ -21,7 +21,10 @@ const saveMoaModels = vi.fn()
 const setEnvVar = vi.fn()
 const getHermesConfigRecord = vi.fn()
 const saveHermesConfig = vi.fn()
+const startManualLocalEndpoint = vi.fn()
+const startManualOnboarding = vi.fn()
 const startManualProviderOAuth = vi.fn()
+let profileSwitchHandler: (() => void) | null = null
 
 vi.mock('@/hermes', () => ({
   getGlobalModelInfo: () => getGlobalModelInfo(),
@@ -38,9 +41,17 @@ vi.mock('@/hermes', () => ({
 }))
 
 vi.mock('@/store/onboarding', () => ({
+  startManualLocalEndpoint: () => startManualLocalEndpoint(),
+  startManualOnboarding: () => startManualOnboarding(),
   startManualProviderOAuth: (slug: string) => startManualProviderOAuth(slug)
 }))
 
+vi.mock('../hooks/use-on-profile-switch', () => ({
+  useOnProfileSwitch: (handler: () => void) => {
+    profileSwitchHandler = handler
+  }
+}))
+
 beforeEach(() => {
   getGlobalModelInfo.mockResolvedValue({ provider: 'nous', model: 'hermes-4' })
   getGlobalModelOptions.mockResolvedValue({
@@ -69,6 +80,7 @@ beforeEach(() => {
 afterEach(() => {
   cleanup()
   vi.clearAllMocks()
+  profileSwitchHandler = null
 })
 
 async function renderModelSettings() {
@@ -98,6 +110,103 @@ describe('ModelSettings', () => {
     expect(screen.queryByText(/DeepSeek/)).toBeNull()
   })
 
+  it.each(['custom', 'local', 'custom:lab'])(
+    'opens local endpoint setup when %s has no inventory row',
+    async provider => {
+      getGlobalModelInfo.mockResolvedValueOnce({ provider, model: '' })
+      getGlobalModelOptions.mockResolvedValueOnce({ providers: [] })
+
+      await renderModelSettings()
+
+      const providerSelect = (await screen.findAllByRole('combobox'))[0]
+
+      expect(providerSelect.textContent).toContain(provider)
+      expect(screen.queryByText(/undefined/)).toBeNull()
+      expect(screen.queryByText(/signs in through your browser/)).toBeNull()
+
+      fireEvent.click(await screen.findByRole('button', { name: 'Set up provider' }))
+
+      expect(startManualLocalEndpoint).toHaveBeenCalledOnce()
+      expect(startManualOnboarding).not.toHaveBeenCalled()
+      expect(startManualProviderOAuth).not.toHaveBeenCalled()
+    }
+  )
+
+  it('opens the generic provider picker for an unknown provider with no inventory row', async () => {
+    getGlobalModelInfo.mockResolvedValueOnce({ provider: 'retired-provider', model: '' })
+    getGlobalModelOptions.mockResolvedValueOnce({ providers: [] })
+
+    await renderModelSettings()
+
+    fireEvent.click(await screen.findByRole('button', { name: 'Set up provider' }))
+
+    expect(startManualOnboarding).toHaveBeenCalledOnce()
+    expect(startManualLocalEndpoint).not.toHaveBeenCalled()
+    expect(startManualProviderOAuth).not.toHaveBeenCalled()
+  })
+
+  it('deep-links a known OAuth provider row into its setup flow', async () => {
+    getGlobalModelInfo.mockResolvedValueOnce({ provider: 'anthropic', model: '' })
+    getGlobalModelOptions.mockResolvedValueOnce({
+      providers: [
+        {
+          name: 'Anthropic',
+          slug: 'anthropic',
+          models: [],
+          authenticated: false,
+          auth_type: 'oauth'
+        }
+      ]
+    })
+
+    await renderModelSettings()
+
+    fireEvent.click(await screen.findByRole('button', { name: 'Set up Anthropic' }))
+
+    expect(startManualProviderOAuth).toHaveBeenCalledWith('anthropic')
+    expect(startManualLocalEndpoint).not.toHaveBeenCalled()
+    expect(startManualOnboarding).not.toHaveBeenCalled()
+  })
+
+  it('replaces the selected provider and model when the active profile changes', async () => {
+    getGlobalModelInfo
+      .mockResolvedValueOnce({ provider: 'custom', model: 'local-a' })
+      .mockResolvedValueOnce({ provider: 'nous', model: 'hermes-4' })
+    getGlobalModelOptions
+      .mockResolvedValueOnce({
+        providers: [
+          {
+            name: 'Custom A',
+            slug: 'custom',
+            models: ['local-a'],
+            authenticated: true
+          }
+        ]
+      })
+      .mockResolvedValueOnce({
+        providers: [
+          {
+            name: 'Nous',
+            slug: 'nous',
+            models: ['hermes-4'],
+            authenticated: true,
+            capabilities: { 'hermes-4': { reasoning: true, fast: true } }
+          }
+        ]
+      })
+
+    await renderModelSettings()
+    expect((await screen.findAllByRole('combobox'))[0].textContent).toContain('Custom A')
+
+    await act(async () => {
+      profileSwitchHandler?.()
+    })
+
+    await waitFor(() => expect(getGlobalModelInfo).toHaveBeenCalledTimes(2))
+    await waitFor(() => expect(screen.getAllByRole('combobox')[0].textContent).toContain('Nous'))
+    expect(screen.queryByRole('button', { name: 'Set up provider' })).toBeNull()
+  })
+
   it('writes the profile default speed (service_tier) when the fast switch is toggled', async () => {
     await renderModelSettings()
     await waitFor(() => expect(getHermesConfigRecord).toHaveBeenCalled())
diff --git a/apps/desktop/src/app/settings/model-settings.tsx b/apps/desktop/src/app/settings/model-settings.tsx
index aba305b78..0b188605c 100644
--- a/apps/desktop/src/app/settings/model-settings.tsx
+++ b/apps/desktop/src/app/settings/model-settings.tsx
@@ -27,7 +27,7 @@ import { useI18n } from '@/i18n'
 import { AlertTriangle, Cpu, Loader2 } from '@/lib/icons'
 import { cn } from '@/lib/utils'
 import { notifyError } from '@/store/notifications'
-import { startManualLocalEndpoint, startManualProviderOAuth } from '@/store/onboarding'
+import { startManualLocalEndpoint, startManualOnboarding, startManualProviderOAuth } from '@/store/onboarding'
 
 import { invalidateHermesConfig, setHermesConfigCache, useHermesConfigRecord } from '../hooks/use-config-record'
 import { useOnProfileSwitch } from '../hooks/use-on-profile-switch'
@@ -220,7 +220,7 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
   // A's models/providers into profile B (or fire onMainModelChanged for A).
   const profileEpoch = useRef(0)
 
-  const refresh = useCallback(async () => {
+  const refresh = useCallback(async ({ replaceSelection = false }: { replaceSelection?: boolean } = {}) => {
     const epoch = profileEpoch.current
     setLoading(true)
     setError('')
@@ -239,8 +239,15 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
 
       setMainModel({ model: modelInfo.model, provider: modelInfo.provider })
       setProviders(modelOptions.providers || [])
-      setSelectedProvider(prev => prev || modelInfo.provider)
-      setSelectedModel(prev => prev || modelInfo.model)
+
+      if (replaceSelection) {
+        setSelectedProvider(modelInfo.provider)
+        setSelectedModel(modelInfo.model)
+      } else {
+        setSelectedProvider(prev => prev || modelInfo.provider)
+        setSelectedModel(prev => prev || modelInfo.model)
+      }
+
       setAuxiliary(auxiliaryModels)
       setMoa(moaModels)
 
@@ -270,11 +277,28 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
   // new profile (bumping the epoch first so any in-flight A request is discarded).
   useOnProfileSwitch(() => {
     profileEpoch.current += 1
-    void refresh()
+    // The panel stays mounted across profile switches, so clear the previous
+    // profile's draft selection before loading the new profile's source of
+    // truth. Ordinary same-profile refreshes still preserve in-progress edits.
+    setSelectedProvider('')
+    setSelectedModel('')
+    setApiKeyDraft('')
+    void refresh({ replaceSelection: true })
   })
 
   const providerOptions = providers.length ? providers : NO_PROVIDERS
 
+  // Radix renders a blank trigger when the controlled value has no matching
+  // item. Keep a missing saved provider visible in the main selector while
+  // leaving it out of the real inventory used for readiness/setup metadata.
+  const mainProviderOptions = useMemo(
+    () =>
+      selectedProvider && !providers.some(provider => provider.slug === selectedProvider)
+        ? [{ name: selectedProvider, slug: selectedProvider, models: [] }, ...providers]
+        : providerOptions,
+    [providerOptions, providers, selectedProvider]
+  )
+
   // MoA reference/aggregator slots must never be the moa virtual provider —
   // that would create a recursive MoA tree (the backend rejects it on save).
   // Hide it from the slot selectors so it isn't offered as a dead choice.
@@ -504,7 +528,7 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
         notifyError(err, m.defaultsFailed)
       }
     },
-    [config, m.defaultsFailed]
+    [config, m.defaultsFailed, setConfig]
   )
 
   // Paste an API key for the selected `api_key` provider, persist it, then
@@ -561,7 +585,8 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
   // local-endpoint form (URL + optional API key) instead of being dead-ended
   // on the OAuth picker (the original "booted back to the first screen" loop).
   const startProviderSetup = useCallback(() => {
-    const slug = selectedProviderRow?.slug
+    const rowSlug = selectedProviderRow?.slug.trim() ?? ''
+    const slug = rowSlug || selectedProvider.trim()
 
     if (!slug) {
       return
@@ -571,10 +596,14 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
 
     if (lower === 'custom' || lower === 'local' || lower.startsWith('custom:')) {
       startManualLocalEndpoint()
+    } else if (rowSlug) {
+      startManualProviderOAuth(rowSlug)
     } else {
-      startManualProviderOAuth(slug)
+      // An absent row has no trustworthy auth metadata. Open the generic
+      // provider picker instead of deep-linking an unknown or stale slug.
+      startManualOnboarding()
     }
-  }, [selectedProviderRow])
+  }, [selectedProvider, selectedProviderRow])
 
   const applyMainModel = useCallback(async () => {
     if (!selectedProvider || !selectedModel) {
@@ -700,7 +729,7 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
               <SelectValue placeholder={m.provider} />
             </SelectTrigger>
             <SelectContent>
-              {providerOptions.map(provider => (
+              {mainProviderOptions.map(provider => (
                 <SelectItem key={provider.slug || 'none'} value={provider.slug || 'none'}>
                   {provider.name}
                 </SelectItem>
@@ -762,7 +791,7 @@ export function ModelSettings({ onMainModelChanged }: ModelSettingsProps) {
             </>
           )}
         </div>
-        {needsSetup && !setupIsApiKey && (
+        {needsSetup && !setupIsApiKey && selectedProviderRow && (
           <p className="mt-2 text-xs text-muted-foreground">
             {selectedProviderRow?.auth_type === 'api_key'
               ? `${selectedProviderRow?.name} needs an API key — set it up to choose a model.`