Problem in request HTTPmethod

I use the HTTP request method to change and update the assigned_id variable of a task, as demonstrated below:

var request = $http({
method: "put",
url: "../API/bpm/humanTask/"+ $scope.properties.taskId,
data: {
"assigned_id" :$scope.properties.userId
}

            }).then(function successCallback(response)
            {
                $http({
                    method: "get",
                    url: ""../API/bpm/humanTask/"+ $scope.properties.taskId,
                }).then(function successCallback(response) {
                    $scope.properties.api = response.data;
                });

            }, function errorCallback(response)
            {
               console.log("error " + angular.toJson(response, true));
            });

But there is a problem if I want to change any other variable in an API, apparently this code only works for assigned_id. Using this same code to change the displayDescription variable nothing occurs. What is the problem? How do I make a code to change other variables from an API? It is possible?