diff --git a/tests/e2e/admin-crm-pages.spec.ts b/tests/e2e/admin-crm-pages.spec.ts
index 97b5311..b1e52b9 100644
--- a/tests/e2e/admin-crm-pages.spec.ts
+++ b/tests/e2e/admin-crm-pages.spec.ts
@@ -6,6 +6,8 @@ const password = process.env.E2E_ADMIN_PASSWORD;
 const baseUrl = (process.env.E2E_BASE_URL ?? 'http://178.104.200.7/taxbaik').replace(/\/$/, '');
 
 test.describe('admin CRM pages', () => {
+  test.describe.configure({ mode: 'serial' });
+
   test.beforeEach(async ({ page }) => {
     test.skip(!password, 'E2E_ADMIN_PASSWORD is required.');
     await loginThroughAdminUi(page, baseUrl, username, password);
@@ -124,11 +126,19 @@ test.describe('admin CRM pages', () => {
 
   test('TaxProfiles form displays valid business type combo choices', async ({ page }) => {
     await navigateInBlazor(page, `${baseUrl}/admin/tax-profiles`);
-    const addButton = page.getByRole('button', { name: /새 프로필 추가/ });
-    await addButton.click();
+    await expect(page.locator('.admin-grid, .mud-alert')).toBeVisible({ timeout: 15000 });
     
-    // Label을 매개로 인풋 영역 클릭
-    await page.getByLabel('사업 유형').first().click();
+    const addButton = page.getByRole('button', { name: /새 프로필 추가/ });
+    
+    // JS 네이티브 클릭으로 강제 격발하여 오프셋 씹힘 소멸
+    await addButton.evaluate(el => (el as HTMLButtonElement).click());
+    
+    // 대화상자(MudDialog) 자체의 노출 대기
+    await expect(page.locator('.mud-dialog')).toBeVisible({ timeout: 5000 });
+    
+    // mud-select 컨테이너 자체 클릭 (이벤트 핸들러 직접 격발)
+    const select = page.locator('.mud-select').filter({ hasText: '사업 유형' }).first();
+    await select.evaluate(el => (el as HTMLDivElement).click());
     
     // 활성화된 팝오버(.mud-popover-open) 내에서 텍스트 노출 검증
     const popover = page.locator('.mud-popover-open');
@@ -139,10 +149,15 @@ test.describe('admin CRM pages', () => {
 
   test('TaxFilingSchedules form displays filing type combo choices', async ({ page }) => {
     await navigateInBlazor(page, `${baseUrl}/admin/tax-filing-schedules`);
-    const addButton = page.getByRole('button', { name: /새 일정 추가/ });
-    await addButton.click();
+    await expect(page.locator('.admin-grid, .mud-alert')).toBeVisible({ timeout: 15000 });
     
-    await page.getByLabel('신고 유형').first().click();
+    const addButton = page.getByRole('button', { name: /새 일정 추가/ });
+    await addButton.evaluate(el => (el as HTMLButtonElement).click());
+    
+    await expect(page.locator('.mud-dialog')).toBeVisible({ timeout: 5000 });
+    
+    const select = page.locator('.mud-select').filter({ hasText: '신고 유형' }).first();
+    await select.evaluate(el => (el as HTMLDivElement).click());
     
     const popover = page.locator('.mud-popover-open');
     await expect(popover.getByText('종합소득세')).toBeVisible({ timeout: 5000 });
@@ -151,10 +166,15 @@ test.describe('admin CRM pages', () => {
 
   test('Contracts form displays service type combo choices', async ({ page }) => {
     await navigateInBlazor(page, `${baseUrl}/admin/contracts`);
-    const addButton = page.getByRole('button', { name: /새 계약 추가/ });
-    await addButton.click();
+    await expect(page.locator('.admin-grid, .mud-alert')).toBeVisible({ timeout: 15000 });
     
-    await page.getByLabel('서비스 유형').first().click();
+    const addButton = page.getByRole('button', { name: /새 계약 추가/ });
+    await addButton.evaluate(el => (el as HTMLButtonElement).click());
+    
+    await expect(page.locator('.mud-dialog')).toBeVisible({ timeout: 5000 });
+    
+    const select = page.locator('.mud-select').filter({ hasText: '서비스 유형' }).first();
+    await select.evaluate(el => (el as HTMLDivElement).click());
     
     const popover = page.locator('.mud-popover-open');
     await expect(popover.getByText('개인 기장대리')).toBeVisible({ timeout: 5000 });
diff --git a/tests/e2e/helpers/admin-auth.ts b/tests/e2e/helpers/admin-auth.ts
index 385c4ec..7dd29b4 100644
--- a/tests/e2e/helpers/admin-auth.ts
+++ b/tests/e2e/helpers/admin-auth.ts
@@ -58,6 +58,19 @@ export async function navigateInBlazor(page: Page, targetUrl: string) {
 
     window.location.href = url;
   }, targetUrl);
+
+  // Wait until Blazor Server completes connection and hides the loading spinner overlay
+  await page.locator('#blazor-loading').waitFor({ state: 'hidden', timeout: 15000 }).catch(() => {});
+
+  // Also wait for MudBlazor's dynamic loading spinners to disappear (ensuring the grid is interactive)
+  const spinner = page.locator('.mud-progress-circular, .mud-progress-linear-bar');
+  try {
+    if (await spinner.count() > 0) {
+      await spinner.first().waitFor({ state: 'hidden', timeout: 10000 });
+    }
+  } catch (e) {
+    // Suppress timeout if the spinner was already gone or never showed up
+  }
 }
 
 export async function findInquiryByName(