diff --git a/src/main/java/uk/gov/hmcts/reform/wataskmanagementapi/services/CFTTaskMapper.java b/src/main/java/uk/gov/hmcts/reform/wataskmanagementapi/services/CFTTaskMapper.java
index 4e485440c9..2fdb04c6ea 100644
--- a/src/main/java/uk/gov/hmcts/reform/wataskmanagementapi/services/CFTTaskMapper.java
+++ b/src/main/java/uk/gov/hmcts/reform/wataskmanagementapi/services/CFTTaskMapper.java
@@ -185,8 +185,8 @@ public TaskResource mapToApiFirstTaskResource(CreateTaskRequestTask request) {
             taskTitle != null ? taskTitle : taskName,
             request.getDescription(),
             new ArrayList<NoteResource>(),
-            majorPriority != null ? majorPriority : 5000,
-            minorPriority != null ? minorPriority : 500,
+            majorPriority,
+            minorPriority,
             null, //Need to get from taskPayload assignee
             false, //autoAssigned
             executionTypeResource,
@@ -915,6 +915,7 @@ public TaskResource mapToTaskResourceForReconfigure(TaskResource taskResource, T
         taskResource.setPriorityDate(task.getPriorityDate());
         taskResource.setMajorPriority(task.getMajorPriority());
         taskResource.setMinorPriority(task.getMinorPriority());
+
         String taskId = task.getId().toString();
         Set<TaskRoleResource> taskRoleResources = mapPermissions(task.getPermissions(), taskId);
         taskResource.setTaskRoleResources(taskRoleResources);
@@ -926,15 +927,23 @@ public TaskResource mapToTaskResourceForReconfigure(TaskResource taskResource, T
         taskResource.setRoleCategory(task.getRoleCategory());
         taskResource.setNextHearingDate(task.getNextHearingDate());
         taskResource.setNextHearingId(task.getNextHearingId());
-        Map<String, String> additionalProperties = Collections.emptyMap();
+        Map<String, String> additionalProperties = new ConcurrentHashMap<>();
+
+        // Start with existing values if present
+        if (taskResource.getAdditionalProperties() != null
+            && !taskResource.getAdditionalProperties().isEmpty()) {
+            additionalProperties.putAll(taskResource.getAdditionalProperties());
+        }
+
+        // Merge / update with new values from task
         if (task.getAdditionalProperties() != null) {
-            additionalProperties = task.getAdditionalProperties().entrySet()
-                .stream()
-                .collect(Collectors.toMap(
-                    Map.Entry::getKey,
-                    e -> String.valueOf(e.getValue())
-                ));
+            task.getAdditionalProperties().forEach(
+                (key, value) -> additionalProperties.put(key, String.valueOf(value)) // put() handles both add & update
+            );
         }
+
+
+        // Set back to resource
         taskResource.setAdditionalProperties(additionalProperties);
         return taskResource;
     }
diff --git a/src/main/resources/api-specs/openapi.yaml b/src/main/resources/api-specs/openapi.yaml
index 391d908ec1..f2eb56f646 100644
--- a/src/main/resources/api-specs/openapi.yaml
+++ b/src/main/resources/api-specs/openapi.yaml
@@ -352,9 +352,11 @@ components:
         major_priority:
           type: integer
           description: Major priority level.
+          default: 5000
         minor_priority:
           type: integer
           description: Minor priority level.
+          default: 500
         location_name:
           type: string
           description: Location display name.
@@ -514,6 +516,10 @@ components:
         - case_name
         - region
         - location
+        - role_category
+        - title
+        - major_priority
+        - minor_priority
       description: Task attributes that can be updated during reconfiguration.
       properties:
         id: