combo box with dynamic value

I can show the combo box now, and store the data in metadata columns, but the option show empty string

            let containerIdx = model.enumerationObject.containers.push({displayName})-1;

            model.enumerationObject.instances.push({
                containerIdx,
                objectName: model.objectName,
                properties: {
                    isMask: this.getValue<boolean>(currentColumn.objects, model.objectName, "isMask", false),
                    background: this.getValue<string>(currentColumn.objects, model.objectName, "background", "#FFFFFF")
                },
                selector: { metadata: currentColumn.queryName }
            });

this happen to with PowerKPIMatrix too, i thing something new with update and make the option did't show the text