diff --git a/src/i18n/resources.ts b/src/i18n/resources.ts
index 2f3b00e..17ac135 100644
--- a/src/i18n/resources.ts
+++ b/src/i18n/resources.ts
@@ -602,6 +602,7 @@ export const zhCN = {
   'agents.oauthLoginRequired.launchDescription': '已开启 OAuth 配置模式，但未检测到有效的 Codex 登录凭据。请先在 Codex 中登录 ChatGPT 账号，然后再启动。',
   'agents.oauthLoginRequired.confirm': '我知道了',
   'agents.modify.apply': '应用配置修改',
+  'agents.modify.update': '更新配置',
   'agents.modify.close': '关闭配置修改',
   'agents.modify.default': '默认配置',
   'agents.modify.clear': '清空配置',
@@ -1560,6 +1561,7 @@ export const en: Record<MessageKey, string> = {
   'agents.oauthLoginRequired.launchDescription': 'OAuth configuration mode is enabled, but no valid Codex sign-in credentials were found. Sign in to your ChatGPT account in Codex before launching it.',
   'agents.oauthLoginRequired.confirm': 'Got it',
   'agents.modify.apply': 'Apply Configuration Changes',
+  'agents.modify.update': 'Update Configuration',
   'agents.modify.close': 'Close Configuration Changes',
   'agents.modify.default': 'Default Configuration',
   'agents.modify.clear': 'Clear Configuration',
diff --git a/src/pages/AgentsPage.tsx b/src/pages/AgentsPage.tsx
index 724ae45..a930831 100644
--- a/src/pages/AgentsPage.tsx
+++ b/src/pages/AgentsPage.tsx
@@ -119,10 +119,16 @@ const createClaudeModelMappings = (model: string): ClaudeModelMappings => ({
   haiku: model,
 });
 
+const sameAgentModel = (left: string, right: string) => (
+  left.trim().toLocaleLowerCase() === right.trim().toLocaleLowerCase()
+);
+
 const sameClaudeModelMappings = (
   left: ClaudeModelMappings,
   right: ClaudeModelMappings,
-) => left.opus === right.opus && left.sonnet === right.sonnet && left.haiku === right.haiku;
+) => sameAgentModel(left.opus, right.opus)
+  && sameAgentModel(left.sonnet, right.sonnet)
+  && sameAgentModel(left.haiku, right.haiku);
 
 const claudeMappingRoles = [
   {
@@ -738,7 +744,7 @@ export function AgentsPage() {
   const modelDraftChanged = !isClaudeModelMappingClient && Boolean(
     selectedModel.trim()
       && appliedModel.trim()
-      && selectedModel.trim() !== appliedModel.trim(),
+      && !sameAgentModel(selectedModel, appliedModel),
   );
   const appliedClaudeModelMappings = (selected === 'claude-code'
     ? activeStatus?.claudeCodeModelMappings
@@ -757,6 +763,8 @@ export function AgentsPage() {
   const oauthConfigurationChanged = selected === 'codex'
     && oauthConfiguration !== Boolean(activeStatus?.oauthConfiguration);
   const draftChanged = modelDraftChanged || claudeMappingDraftChanged || oauthConfigurationChanged;
+  const configurationUpdateRequired = activeStatus?.modificationState === 'applied'
+    && draftChanged;
   const canEnable = Boolean(
     activeStatus?.supportedPlatform
       && activeStatus.installed
@@ -1446,20 +1454,26 @@ export function AgentsPage() {
                     <button
                       type="button"
                       className="primary-button"
-                      onClick={() => void (activeStatus?.modificationState === 'applied'
-                        ? closeConfigurationChanges()
-                        : applyConfigurationChanges())}
+                      onClick={() => void (configurationUpdateRequired
+                        ? applyConfigurationChanges()
+                        : activeStatus?.modificationState === 'applied'
+                          ? closeConfigurationChanges()
+                          : applyConfigurationChanges())}
                       disabled={
                         busy
-                        || (activeStatus?.modificationState === 'applied' ? false : !canEnable)
+                        || (activeStatus?.modificationState === 'applied' && !configurationUpdateRequired
+                          ? false
+                          : !canEnable)
                       }
                     >
                       {busyAction === 'apply' || busyAction === 'close-config'
                         ? <LoaderCircle size={16} className="spin" />
                         : null}
-                      {activeStatus?.modificationState === 'applied'
-                        ? t('agents.modify.close')
-                        : t('agents.modify.apply')}
+                      {configurationUpdateRequired
+                        ? t('agents.modify.update')
+                        : activeStatus?.modificationState === 'applied'
+                          ? t('agents.modify.close')
+                          : t('agents.modify.apply')}
                     </button>
                     <button
                       type="button"