diff --git a/catalystwan/models/configuration/feature_profile/common.py b/catalystwan/models/configuration/feature_profile/common.py
index a9d1c1a1..b1d30422 100644
--- a/catalystwan/models/configuration/feature_profile/common.py
+++ b/catalystwan/models/configuration/feature_profile/common.py
@@ -194,9 +194,7 @@ class WANIPv4StaticRoute(BaseModel):
     gateway: Global[Literal["nextHop", "null0", "dhcp"]] = Field(
         default=Global(value="nextHop"), serialization_alias="gateway", validation_alias="gateway"
     )
-    next_hops: Optional[List[NextHop]] = Field(
-        default_factory=list, serialization_alias="nextHop", validation_alias="nextHop"
-    )
+    next_hops: Optional[List[NextHop]] = Field(default=None, serialization_alias="nextHop", validation_alias="nextHop")
     distance: Optional[Global[int]] = Field(default=None, serialization_alias="distance", validation_alias="distance")
 
     def set_to_next_hop(
diff --git a/catalystwan/models/configuration/feature_profile/sdwan/system/logging_parcel.py b/catalystwan/models/configuration/feature_profile/sdwan/system/logging_parcel.py
index e13ead03..e70dbb4f 100644
--- a/catalystwan/models/configuration/feature_profile/sdwan/system/logging_parcel.py
+++ b/catalystwan/models/configuration/feature_profile/sdwan/system/logging_parcel.py
@@ -81,11 +81,9 @@ class LoggingParcel(_ParcelBase):
         populate_by_name=True,
     )
     disk: Disk = Field(default_factory=Disk, validation_alias=AliasPath("data", "disk"))
-    tls_profile: Optional[List[TlsProfile]] = Field(
-        default_factory=list, validation_alias=AliasPath("data", "tlsProfile")
-    )
-    server: Optional[List[Server]] = Field(default_factory=list, validation_alias=AliasPath("data", "server"))
-    ipv6_server: Optional[List[Server]] = Field(default_factory=list, validation_alias=AliasPath("data", "ipv6Server"))
+    tls_profile: Optional[List[TlsProfile]] = Field(default=None, validation_alias=AliasPath("data", "tlsProfile"))
+    server: Optional[List[Server]] = Field(default=None, validation_alias=AliasPath("data", "server"))
+    ipv6_server: Optional[List[Server]] = Field(default=None, validation_alias=AliasPath("data", "ipv6Server"))
 
     def set_disk(self, enable: bool, disk_file_size: int = 10, disk_file_rotate: int = 10):
         self.disk.disk_enable = as_global(enable)
diff --git a/catalystwan/models/configuration/feature_profile/sdwan/topology/custom_control.py b/catalystwan/models/configuration/feature_profile/sdwan/topology/custom_control.py
index 6c818f2d..8bb837d2 100644
--- a/catalystwan/models/configuration/feature_profile/sdwan/topology/custom_control.py
+++ b/catalystwan/models/configuration/feature_profile/sdwan/topology/custom_control.py
@@ -181,7 +181,7 @@ class Actions(BaseModel):
 
 class Sequence(BaseModel):
     model_config = ConfigDict(populate_by_name=True)
-    actions: Optional[List[Actions]] = Field(default_factory=list)
+    actions: Optional[List[Actions]] = Field(default=None)
     base_action: Optional[Global[AcceptRejectActionType]] = Field(
         default=None, validation_alias="baseAction", serialization_alias="baseAction"
     )
diff --git a/catalystwan/models/policy/definition/url_filtering.py b/catalystwan/models/policy/definition/url_filtering.py
index d033030b..1d5b4ad6 100644
--- a/catalystwan/models/policy/definition/url_filtering.py
+++ b/catalystwan/models/policy/definition/url_filtering.py
@@ -41,7 +41,7 @@ class UrlFilteringDefinition(BaseModel):
     logging: List[str] = Field(default_factory=list)
     enable_alerts: bool = Field(validation_alias="enableAlerts", serialization_alias="enableAlerts")
     alerts: Set[UrlFilteringAlerts] = Field(
-        default_factory=list, validation_alias="alerts", serialization_alias="alerts"
+        default_factory=set, validation_alias="alerts", serialization_alias="alerts"
     )
     target_vpns: List[VpnId] = Field(
         default_factory=list, validation_alias="targetVpns", serialization_alias="targetVpns"
diff --git a/catalystwan/models/policy/list/identity.py b/catalystwan/models/policy/list/identity.py
index ef6aeb9c..d57dd51d 100644
--- a/catalystwan/models/policy/list/identity.py
+++ b/catalystwan/models/policy/list/identity.py
@@ -9,8 +9,8 @@
 
 class IdentityListEntry(BaseModel):
     model_config = ConfigDict(populate_by_name=True)
-    user: str = Field(default=None)
-    user_group: str = Field(default=None, validation_alias="userGroup", serialization_alias="userGroup")
+    user: str
+    user_group: str = Field(validation_alias="userGroup", serialization_alias="userGroup")
 
 
 class IdentityList(PolicyListBase):