diff --git a/bot/handlers/user/payment.py b/bot/handlers/user/payment.py
index 8d2f3c7..25f358d 100644
--- a/bot/handlers/user/payment.py
+++ b/bot/handlers/user/payment.py
@@ -624,7 +624,7 @@ async def yookassa_webhook_route(request: web.Request):
             logging.error(
                 f"YooKassa webhook payment {payment_data_from_notification.id} lacks metadata. Cannot process."
             )
-            return web.Response(status=503, text="yookassa_missing_metadata")
+            return web.Response(status=200, text="yookassa_missing_metadata")
 
         # Safely extract payment_method details (SDK objects may not have to_dict)
         pm_obj = getattr(payment_data_from_notification, 'payment_method', None)
diff --git a/db/alembic_runner.py b/db/alembic_runner.py
index 38deb04..92129d4 100644
--- a/db/alembic_runner.py
+++ b/db/alembic_runner.py
@@ -67,6 +67,45 @@ def _run_legacy_migrator_compatibility(connection: Connection) -> None:
         for column in inspect(connection).get_columns("users")
     }
     if "referral_code" in users_columns:
+        connection.execute(
+            text(
+                """
+                UPDATE users
+                SET referral_code = NULLIF(UPPER(BTRIM(referral_code)), '')
+                WHERE referral_code IS NOT NULL
+                """
+            )
+        )
+        connection.execute(
+            text(
+                """
+                WITH duplicate_codes AS (
+                    SELECT
+                        user_id,
+                        ROW_NUMBER() OVER (
+                            PARTITION BY referral_code
+                            ORDER BY user_id
+                        ) AS rn
+                    FROM users
+                    WHERE referral_code IS NOT NULL
+                )
+                UPDATE users AS u
+                SET referral_code = UPPER(
+                    SUBSTRING(
+                        md5(
+                            u.user_id::text
+                            || clock_timestamp()::text
+                            || random()::text
+                        )
+                        FROM 1 FOR 9
+                    )
+                )
+                FROM duplicate_codes AS d
+                WHERE u.user_id = d.user_id
+                  AND d.rn > 1
+                """
+            )
+        )
         connection.execute(
             text(
                 """
@@ -84,7 +123,7 @@ def _run_legacy_migrator_compatibility(connection: Connection) -> None:
                             )
                         ) AS referral_code
                     FROM users
-                    WHERE referral_code IS NULL OR referral_code = ''
+                    WHERE referral_code IS NULL
                 )
                 UPDATE users AS u
                 SET referral_code = g.referral_code
@@ -102,16 +141,6 @@ def _run_legacy_migrator_compatibility(connection: Connection) -> None:
                 """
             )
         )
-        connection.execute(
-            text(
-                """
-                UPDATE users
-                SET referral_code = UPPER(referral_code)
-                WHERE referral_code IS NOT NULL
-                  AND referral_code <> UPPER(referral_code)
-                """
-            )
-        )
 
     db_inspector = inspect(connection)
     if db_inspector.has_table("payments"):
diff --git a/db/dal/payment_dal.py b/db/dal/payment_dal.py
index 1c79525..18452f7 100644
--- a/db/dal/payment_dal.py
+++ b/db/dal/payment_dal.py
@@ -225,7 +225,14 @@ async def mark_provider_payment_processing_once(
         Payment.status != "processing",
     ]
     if expected_status_prefix:
-        conditions.append(Payment.status.like(f"{expected_status_prefix}%"))
+        if expected_status_prefix == "pending":
+            # YooKassa may keep authorized payments in waiting_for_capture
+            # before reporting a final successful capture webhook.
+            conditions.append(
+                Payment.status.in_(("waiting_for_capture", "pending", "pending_yookassa"))
+            )
+        else:
+            conditions.append(Payment.status.like(f"{expected_status_prefix}%"))
 
     stmt = (
         update(Payment)