diff --git a/app/cabinet/auth/telegram_auth.py b/app/cabinet/auth/telegram_auth.py
index f4de0e68..716c7ddb 100644
--- a/app/cabinet/auth/telegram_auth.py
+++ b/app/cabinet/auth/telegram_auth.py
@@ -49,7 +49,17 @@ def validate_telegram_login_widget(data: dict[str, Any], max_age_seconds: int =
         auth_time = datetime.fromtimestamp(int(auth_date), tz=UTC)
         age = (datetime.now(UTC) - auth_time).total_seconds()
         if age > max_age_seconds or age < -_MAX_CLOCK_SKEW_SECONDS:
+            logger.warning(
+                'Telegram widget auth rejected: too old',
+                age_hours=round(age / 3600, 1),
+                max_age_hours=round(max_age_seconds / 3600, 1),
+            )
             return False
+        if age > 86400:
+            logger.info(
+                'Telegram widget auth accepted with stale auth_date',
+                age_hours=round(age / 3600, 1),
+            )
     except (ValueError, TypeError, OSError):
         return False
 
@@ -96,7 +106,17 @@ def validate_telegram_init_data(init_data: str, max_age_seconds: int = 86400) ->
             auth_time = datetime.fromtimestamp(int(auth_date), tz=UTC)
             age = (datetime.now(UTC) - auth_time).total_seconds()
             if age > max_age_seconds or age < -_MAX_CLOCK_SKEW_SECONDS:
+                logger.warning(
+                    'Telegram initData rejected: too old',
+                    age_hours=round(age / 3600, 1),
+                    max_age_hours=round(max_age_seconds / 3600, 1),
+                )
                 return None
+            if age > 86400:
+                logger.info(
+                    'Telegram initData accepted with stale auth_date (Telegram caching bug)',
+                    age_hours=round(age / 3600, 1),
+                )
         except (ValueError, TypeError, OSError):
             return None
 
diff --git a/app/cabinet/routes/account_linking.py b/app/cabinet/routes/account_linking.py
index 4ed3c8fe..3424161f 100644
--- a/app/cabinet/routes/account_linking.py
+++ b/app/cabinet/routes/account_linking.py
@@ -487,7 +487,8 @@ async def link_telegram(
 
     if request.init_data:
         # Mini App flow: validate initData
-        user_data = validate_telegram_init_data(request.init_data)
+        # Generous max_age: Telegram Desktop/iOS cache initData with stale auth_date
+        user_data = validate_telegram_init_data(request.init_data, max_age_seconds=86400 * 30)
         if not user_data or not user_data.get('id'):
             raise HTTPException(
                 status_code=status.HTTP_400_BAD_REQUEST,
@@ -560,7 +561,8 @@ async def link_telegram(
         if request.photo_url is not None:
             widget_data['photo_url'] = request.photo_url
 
-        if not validate_telegram_login_widget(widget_data):
+        # Generous max_age: Telegram caches auth data with stale auth_date
+        if not validate_telegram_login_widget(widget_data, max_age_seconds=86400 * 30):
             raise HTTPException(
                 status_code=status.HTTP_400_BAD_REQUEST,
                 detail='Invalid or expired Telegram Login Widget data',
diff --git a/app/cabinet/routes/auth.py b/app/cabinet/routes/auth.py
index a69ba16c..85e5ab22 100644
--- a/app/cabinet/routes/auth.py
+++ b/app/cabinet/routes/auth.py
@@ -431,7 +431,11 @@ async def auth_telegram(
             detail='Too many requests',
             headers={'Retry-After': '60'},
         )
-    user_data = validate_telegram_init_data(request.init_data)
+    # Telegram Desktop/iOS cache initData with stale auth_date (known Telegram bug:
+    # https://github.com/telegramdesktop/tdesktop/issues/28303).
+    # Use generous max_age: HMAC signature proves authenticity,
+    # JWT tokens handle actual session expiration after login.
+    user_data = validate_telegram_init_data(request.init_data, max_age_seconds=86400 * 30)
 
     if not user_data:
         raise HTTPException(
@@ -550,7 +554,8 @@ async def auth_telegram_widget(
 
     widget_data = request.model_dump(exclude={'campaign_slug', 'referral_code'})
 
-    if not validate_telegram_login_widget(widget_data):
+    # Generous max_age: Telegram caches auth data with stale auth_date
+    if not validate_telegram_login_widget(widget_data, max_age_seconds=86400 * 30):
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail='Invalid or expired Telegram authentication data',