diff --git a/src/popup/sections/GeneralPart.jsx b/src/popup/sections/GeneralPart.jsx
index 28b51b71e..bf1798b89 100644
--- a/src/popup/sections/GeneralPart.jsx
+++ b/src/popup/sections/GeneralPart.jsx
@@ -1,7 +1,7 @@
 import { useTranslation } from 'react-i18next'
 import { useLayoutEffect, useRef, useState } from 'react'
 import FileSaver from 'file-saver'
-import { isApiModeSelected, getApiModesFromConfig } from '../../utils/index.mjs'
+import { getApiModesFromConfig, modelNameToDesc } from '../../utils/index.mjs'
 import {
   isUsingAzureOpenAiApiModel,
   isUsingClaudeApiModel,
@@ -21,7 +21,11 @@ import { config as menuConfig } from '../../content-script/menu-tools'
 import { PencilIcon } from '@primer/octicons-react'
 import { importDataIntoStorage } from './import-data-cleanup.mjs'
 import { resolveOpenAICompatibleRequest } from '../../services/apis/provider-registry.mjs'
-import { getApiModeDisplayLabel } from './api-modes-provider-utils.mjs'
+import {
+  getApiModeDisplayLabel,
+  getSelectedApiModeOptionValue,
+  UNMATCHED_API_MODE_VALUE,
+} from './api-modes-provider-utils.mjs'
 import {
   buildProviderOverrideFinalConfigUpdate,
   createProviderApiKeyDraftSelectionSignature,
@@ -107,6 +111,14 @@ export function GeneralPart({
     config.apiMode && typeof config.apiMode === 'object'
       ? { apiMode: config.apiMode }
       : { modelName: config.modelName }
+  const selectedApiModeValue = getSelectedApiModeOptionValue(apiModes, config)
+  const currentApiModeLabel = config.apiMode
+    ? getApiModeDisplayLabel(
+        config.apiMode,
+        t,
+        Array.isArray(config.customOpenAIProviders) ? config.customOpenAIProviders : [],
+      ) || t(Models.customModel.desc)
+    : modelNameToDesc(config.modelName, t, config.customModelName)
   const selectedProviderRequest = resolveOpenAICompatibleRequest(config, selectedProviderSession)
   const selectedProviderId = selectedProviderRequest?.providerId || ''
   const selectedProviderSecretTargetId = resolveProviderSecretTargetId(selectedProviderRequest)
@@ -480,15 +492,26 @@ export function GeneralPart({
                 : undefined
             }
             required
+            value={selectedApiModeValue}
             onChange={(e) => {
+              if (e.target.value === UNMATCHED_API_MODE_VALUE) return
               if (e.target.value === '-1') {
                 updateConfig({ modelName: 'customModel', apiMode: null })
                 return
               }
-              const apiMode = apiModes[e.target.value]
-              updateConfig({ apiMode: apiMode })
+              const apiMode = apiModes[Number(e.target.value)]
+              if (!apiMode) {
+                e.currentTarget.value = selectedApiModeValue
+                return
+              }
+              updateConfig({ apiMode })
             }}
           >
+            {selectedApiModeValue === UNMATCHED_API_MODE_VALUE && (
+              <option value={UNMATCHED_API_MODE_VALUE} disabled>
+                {currentApiModeLabel}
+              </option>
+            )}
             {apiModes.map((apiMode, index) => {
               const desc = getApiModeDisplayLabel(
                 apiMode,
@@ -497,15 +520,13 @@ export function GeneralPart({
               )
               if (desc) {
                 return (
-                  <option value={index} key={index} selected={isApiModeSelected(apiMode, config)}>
+                  <option value={index} key={index}>
                     {desc}
                   </option>
                 )
               }
             })}
-            <option value={-1} selected={!config.apiMode && config.modelName === 'customModel'}>
-              {t(Models.customModel.desc)}
-            </option>
+            <option value={-1}>{t(Models.customModel.desc)}</option>
           </select>
           {isUsingMultiModeModel(config) && (
             <select
diff --git a/src/popup/sections/api-modes-provider-utils.mjs b/src/popup/sections/api-modes-provider-utils.mjs
index 59446e463..8fb7e91c4 100644
--- a/src/popup/sections/api-modes-provider-utils.mjs
+++ b/src/popup/sections/api-modes-provider-utils.mjs
@@ -1,5 +1,18 @@
 import { AlwaysCustomGroups } from '../../config/index.mjs'
-import { apiModeToModelName, modelNameToDesc } from '../../utils/model-name-convert.mjs'
+import {
+  apiModeToModelName,
+  getUniquelySelectedApiModeIndex,
+  modelNameToDesc,
+} from '../../utils/model-name-convert.mjs'
+
+export const UNMATCHED_API_MODE_VALUE = '__current-api-mode__'
+
+export function getSelectedApiModeOptionValue(apiModes, configOrSession) {
+  const selectedIndex = getUniquelySelectedApiModeIndex(apiModes, configOrSession)
+  if (selectedIndex !== -1) return String(selectedIndex)
+  if (!configOrSession?.apiMode && configOrSession?.modelName === 'customModel') return '-1'
+  return UNMATCHED_API_MODE_VALUE
+}
 
 function normalizeText(value) {
   return String(value || '').trim()
diff --git a/tests/unit/popup/api-modes-provider-utils.test.mjs b/tests/unit/popup/api-modes-provider-utils.test.mjs
index 3c959be67..167dc4732 100644
--- a/tests/unit/popup/api-modes-provider-utils.test.mjs
+++ b/tests/unit/popup/api-modes-provider-utils.test.mjs
@@ -8,6 +8,7 @@ import {
   createProviderId,
   getConversationAiName,
   getApiModeDisplayLabel,
+  getSelectedApiModeOptionValue,
   getConfiguredCustomApiModesForSessionRecovery,
   getProviderDeleteDisabledReasonKey,
   isProviderEndpointRewriteBlockedBySavedConversations,
@@ -29,9 +30,94 @@ import {
   shouldIncludeSelectedApiModeInReferenceCheck,
   shouldPersistDeletedProviderChanges,
   shouldPersistPendingProviderChanges,
+  UNMATCHED_API_MODE_VALUE,
   validateProviderEndpointDraft,
 } from '../../../src/popup/sections/api-modes-provider-utils.mjs'
 
+test('getSelectedApiModeOptionValue returns the selected active mode index', () => {
+  const apiModes = [
+    {
+      groupName: 'claudeWebModelKeys',
+      itemName: 'claude2WebFree',
+      active: true,
+    },
+    {
+      groupName: 'openRouterApiModelKeys',
+      itemName: 'openRouter_auto',
+      active: true,
+    },
+  ]
+
+  assert.equal(getSelectedApiModeOptionValue(apiModes, { apiMode: { ...apiModes[1] } }), '1')
+})
+
+test('getSelectedApiModeOptionValue preserves an unmatched modelName', () => {
+  const apiModes = [
+    {
+      groupName: 'claudeWebModelKeys',
+      itemName: 'claude2WebFree',
+      active: true,
+    },
+  ]
+
+  assert.equal(
+    getSelectedApiModeOptionValue(apiModes, { modelName: 'chatgptFree35', apiMode: null }),
+    UNMATCHED_API_MODE_VALUE,
+  )
+})
+
+test('getSelectedApiModeOptionValue preserves an unmatched apiMode', () => {
+  const apiModes = [
+    {
+      groupName: 'openRouterApiModelKeys',
+      itemName: 'openRouter_auto',
+      active: true,
+    },
+  ]
+  const selectedApiMode = {
+    groupName: 'openRouterApiModelKeys',
+    itemName: 'openRouter_openai_gpt_5_5',
+    active: true,
+  }
+
+  assert.equal(
+    getSelectedApiModeOptionValue(apiModes, { apiMode: selectedApiMode }),
+    UNMATCHED_API_MODE_VALUE,
+  )
+})
+
+test('getSelectedApiModeOptionValue preserves a selection when no modes are active', () => {
+  const selectedApiMode = {
+    groupName: 'openRouterApiModelKeys',
+    itemName: 'openRouter_openai_gpt_5_5',
+    active: true,
+  }
+
+  assert.equal(
+    getSelectedApiModeOptionValue([], { apiMode: selectedApiMode }),
+    UNMATCHED_API_MODE_VALUE,
+  )
+})
+
+test('getSelectedApiModeOptionValue preserves an ambiguous selection', () => {
+  const duplicateApiMode = {
+    groupName: 'openRouterApiModelKeys',
+    itemName: 'openRouter_auto',
+    active: true,
+  }
+
+  assert.equal(
+    getSelectedApiModeOptionValue([{ ...duplicateApiMode }, { ...duplicateApiMode }], {
+      apiMode: duplicateApiMode,
+    }),
+    UNMATCHED_API_MODE_VALUE,
+  )
+})
+
+test('getSelectedApiModeOptionValue keeps the custom model option selected', () => {
+  assert.equal(getSelectedApiModeOptionValue([], { modelName: 'customModel', apiMode: null }), '-1')
+})
+
 test('createProviderId avoids reserved and existing ids', () => {
   const existingProviders = [{ id: 'foo' }, { id: 'foo-2' }]
   const reservedProviderIds = ['openai', 'deepseek']
@@ -1977,6 +2063,19 @@ test('getApiModeDisplayLabel falls back for legacy custom provider', () => {
   assert.equal(getApiModeDisplayLabel(apiMode, t, []), 'Custom Model (deepseek-v3.2)')
 })
 
+test('getApiModeDisplayLabel falls back when a custom provider is missing', () => {
+  const apiMode = {
+    groupName: 'customApiModelKeys',
+    itemName: 'customModel',
+    isCustom: true,
+    customName: 'deepseek-v3.2',
+    providerId: 'missing-provider',
+  }
+  const t = (value) => value
+
+  assert.equal(getApiModeDisplayLabel(apiMode, t, []), 'Custom Model (deepseek-v3.2)')
+})
+
 test('removePendingProviderDeletion removes a recreated provider id from pending deletions', () => {
   assert.deepEqual(removePendingProviderDeletion(['provider-a', 'provider-b'], ' provider-b '), [
     'provider-a',