Field customfield (Text Area) on WS : core_course_update_courses

Dear Moodle Communities, 

I have a problem using Moodle Web Service : core_course_update_courses, i want to update custom course field data with type : Text Area custom field. I test run this WS in postman.

I already tried this parameters : 

WS Function : core_course_update_courses
courses[0][id] : (id courses)
courses[0][customfields][0][shortname] : bcld_learningobjective
courses[0][customfields][0][value] : This is learning objectives.

This type of custom fields : bcld_learningobjective , is text area. If i changed the type of custom field to short text and i called again the web services and data will updated.

Thank you Moodle Communities.