Minha alteração

src/app/interceptors/session.interceptor.ts

@@ -3,6 +3,7 @@ import { inject, PLATFORM_ID } from '@angular/core';
 import { isPlatformBrowser } from '@angular/common';
 import { catchError, throwError } from 'rxjs';
 import { SessionNoticeService } from '../services/session-notice.service';
+import { AuthService } from '../services/auth.service';
 
 export const sessionInterceptor: HttpInterceptorFn = (req, next) => {
   const platformId = inject(PLATFORM_ID);
@@ -11,11 +12,18 @@ export const sessionInterceptor: HttpInterceptorFn = (req, next) => {
   }
 
   const sessionNotice = inject(SessionNoticeService);
+  const authService = inject(AuthService);
+
+  const url = (req.url || '').toLowerCase();
+  const isAuthRequest = url.includes('/auth/login') || url.includes('/auth/register');
 
   return next(req).pipe(
     catchError((err: HttpErrorResponse) => {
       if (err?.status === 401) {
+        // 401 durante /auth/login = credenciais inválidas, não "sessão expirada".
+        if (!isAuthRequest && !!authService.token) {
           sessionNotice.handleUnauthorized();
+        }
       } else if (err?.status === 403) {
         sessionNotice.handleForbidden();
       }