diff --git a/app/adapters/delivery_providers/cse/client.py b/app/adapters/delivery_providers/cse/client.py
index c28fa19..51a3f15 100644
--- a/app/adapters/delivery_providers/cse/client.py
+++ b/app/adapters/delivery_providers/cse/client.py
@@ -179,6 +179,7 @@ class CSEClient:
                     "cse_request_server_error",
                     operation=operation,
                     status_code=response.status_code,
+                    response_excerpt=_response_excerpt(response.text),
                 )
                 raise CSEClientError(
                     f"CSE {operation} request failed with status "
@@ -233,6 +234,10 @@ class CSEClient:
         return self._retry_backoff_seconds * (2**attempt)
 
 
+def _response_excerpt(text: str, *, limit: int = 1000) -> str:
+    return " ".join(text.split())[:limit]
+
+
 class CSEProvider(DeliveryProvider):
     name = CSE_PROVIDER_NAME
 
diff --git a/app/adapters/delivery_providers/cse/soap.py b/app/adapters/delivery_providers/cse/soap.py
index d4ca74f..c5b8574 100644
--- a/app/adapters/delivery_providers/cse/soap.py
+++ b/app/adapters/delivery_providers/cse/soap.py
@@ -1,9 +1,10 @@
 """SOAP (cargo3) Element serialization and parsing for CSE.
 
 CSE exposes a SOAP/1C web service ("Карго") that transfers data through nested
-universal ``Element`` structures (``Key``/``Value``/``ValueType``/``Fields``/
-``List``/``Tables``/``Properties``). This module builds request envelopes and
-parses responses into a plain Python representation that mappers can navigate.
+universal ``Element`` structures (``Key``/``Value``/``ValueType``/
+``Properties``/``Fields``/``List``/``Tables``). This module builds request
+envelopes and parses responses into a plain Python representation that mappers
+can navigate.
 """
 
 from __future__ import annotations
@@ -15,8 +16,6 @@ from xml.etree import ElementTree as ET
 CARGO_NS = "http://www.cargo3.ru"
 SOAP_NS = "http://www.w3.org/2003/05/soap-envelope"
 
-# Child tags of an Element that hold nested Element lists.
-_LIST_TAGS = ("Fields", "List", "Tables", "Properties")
 _SCALAR_TAGS = ("Key", "Value", "ValueType")
 _BINARY_TAG = "BData"
 
@@ -102,14 +101,14 @@ def _append_element(parent: ET.Element, tag: str, element: Element) -> None:
         _scalar(node, "Value", element.value)
     if element.value_type is not None:
         _scalar(node, "ValueType", element.value_type)
+    for child in element.properties:
+        _append_element(node, "Properties", child)
     for child in element.fields:
         _append_element(node, "Fields", child)
     for child in element.items:
         _append_element(node, "List", child)
     for child in element.tables:
         _append_element(node, "Tables", child)
-    for child in element.properties:
-        _append_element(node, "Properties", child)
 
 
 def _scalar(parent: ET.Element, tag: str, text: str) -> None:
diff --git a/app/domain/payment_notifications.py b/app/domain/payment_notifications.py
index c78b9bd..da2a68d 100644
--- a/app/domain/payment_notifications.py
+++ b/app/domain/payment_notifications.py
@@ -5,7 +5,7 @@ from enum import Enum
 
 class TBankPaymentNotificationAction(str, Enum):
     ACKNOWLEDGE_ONLY = "acknowledge_only"
-    REGISTER_CDEK_ORDER = "register_cdek_order"
+    REGISTER_PROVIDER_ORDER = "register_provider_order"
 
 
 def resolve_tbank_payment_notification_action(
@@ -15,7 +15,7 @@ def resolve_tbank_payment_notification_action(
     error_code: str,
 ) -> TBankPaymentNotificationAction:
     if status == "CONFIRMED" and success is True and error_code == "0":
-        return TBankPaymentNotificationAction.REGISTER_CDEK_ORDER
+        return TBankPaymentNotificationAction.REGISTER_PROVIDER_ORDER
     return TBankPaymentNotificationAction.ACKNOWLEDGE_ONLY
 
 
diff --git a/tests/adapters/delivery_providers/cse/test_cse_adapter.py b/tests/adapters/delivery_providers/cse/test_cse_adapter.py
index 642fc23..8389512 100644
--- a/tests/adapters/delivery_providers/cse/test_cse_adapter.py
+++ b/tests/adapters/delivery_providers/cse/test_cse_adapter.py
@@ -7,6 +7,7 @@ import pytest
 
 from app.adapters.delivery_providers.cse import (
     CSEClient,
+    CSEClientError,
     CSEProvider,
     CSERequestError,
 )
@@ -314,6 +315,37 @@ def test_build_envelope_contains_credentials_and_payload() -> None:
     assert "geo-2" in text
 
 
+def test_save_order_envelope_serializes_properties_before_fields() -> None:
+    body = order_mapper.map_cse_save_order_request(
+        make_init_payment_request(
+            systemData={
+                "tariff": {
+                    "provider": "cse",
+                    "serviceName": "Экспресс",
+                    "price": 200000,
+                    "deliveryDaysMin": 1,
+                    "deliveryDaysMax": 2,
+                    "tariffCode": "ДоставкаДоДверей|tariff-guid-2|urg-exp",
+                },
+                "parcelType": "parcel",
+                "weight": "1.0",
+                "dimensions": {"length": "10", "width": "10", "height": "10"},
+            }
+        ),
+        "order-uuid-1",
+        _params(),
+    )
+
+    text = build_envelope(
+        "SaveDocuments", login="test", password="2016", body=body
+    ).decode("utf-8")
+
+    order_start = text.index("<m:Key>Order</m:Key>")
+    properties_index = text.index("<m:Properties>", order_start)
+    fields_index = text.index("<m:Fields>", order_start)
+    assert properties_index < fields_index
+
+
 def test_parse_calc_response_round_trip() -> None:
     root = parse_response(_CALC_RESPONSE, "Calc")
     assert root.key == "Calc"
@@ -580,3 +612,59 @@ def test_application_error_in_response_raises_request_error() -> None:
 
     with pytest.raises(CSERequestError):
         asyncio.run(provider.get_prices(_calc_request()))
+
+
+def test_server_error_logs_response_excerpt(monkeypatch: pytest.MonkeyPatch) -> None:
+    warning_calls: list[dict[str, Any]] = []
+
+    def capture_warning(event: str, **kwargs: Any) -> None:
+        warning_calls.append({"event": event, **kwargs})
+
+    monkeypatch.setattr(
+        "app.adapters.delivery_providers.cse.client.log.warning",
+        capture_warning,
+    )
+    response = httpx.Response(
+        500,
+        text="<fault>\n CSE rejected SaveDocuments because field X is invalid \n</fault>",
+    )
+    client, _ = _build_client([response])
+    provider = CSEProvider(client)
+
+    with pytest.raises(CSEClientError):
+        asyncio.run(
+            provider.register_order(
+                make_init_payment_request(
+                    systemData={
+                        "tariff": {
+                            "provider": "cse",
+                            "serviceName": "Экспресс",
+                            "price": 200000,
+                            "deliveryDaysMin": 1,
+                            "deliveryDaysMax": 2,
+                            "tariffCode": "ДоставкаДоДверей|tariff-guid-2|urg-exp",
+                        },
+                        "parcelType": "parcel",
+                        "weight": "1.0",
+                        "dimensions": {
+                            "length": "10",
+                            "width": "10",
+                            "height": "10",
+                        },
+                    }
+                ),
+                "order-uuid-1",
+            )
+        )
+
+    assert warning_calls == [
+        {
+            "event": "cse_request_server_error",
+            "operation": "SaveDocuments",
+            "status_code": 500,
+            "response_excerpt": (
+                "<fault> CSE rejected SaveDocuments because field X is invalid "
+                "</fault>"
+            ),
+        }
+    ]
diff --git a/tests/domain/test_payment_notifications.py b/tests/domain/test_payment_notifications.py
index c55e0b4..8fc4efd 100644
--- a/tests/domain/test_payment_notifications.py
+++ b/tests/domain/test_payment_notifications.py
@@ -5,14 +5,14 @@ from app.domain.payment_notifications import (
 )
 
 
-def test_confirmed_success_zero_error_code_registers_cdek_order() -> None:
+def test_confirmed_success_zero_error_code_registers_provider_order() -> None:
     result = resolve_tbank_payment_notification_action(
         status="CONFIRMED",
         success=True,
         error_code="0",
     )
 
-    assert result is TBankPaymentNotificationAction.REGISTER_CDEK_ORDER
+    assert result is TBankPaymentNotificationAction.REGISTER_PROVIDER_ORDER
 
 
 def test_confirmed_without_success_acknowledges_only() -> None: