OData - CompleteWorkitem returns the error "This task cannot be updated..."
Dear all,
I have a question regarding completing the work items. I have a work item which includes a custom EnumeratedType attribute "MySize".

When I try to complete the activity using the OOTB Endpoint from Workflow Domain, I am getting an error that the enumerated type is not supported like below:
"This task cannot be updated.Variable type ext.dropdown.MySize is not supported."

URL: {{baseUrl}}/WorkItems('{{WorkItemId}}')/PTC.Workflow.CompleteWorkitem
Request Body:
Thanks in advance!

