Update Scheduler Resources/Events

An initial scheduler is generated using default data no problem. After user interaction with checkboxes outside the scheduler there is a need to refetch the resources/events to refresh the scheduler. When attempting to assign the new data to this.dp.resources the following message is produced:

message: "Cannot set properties of undefined (setting 'resources')"
stack: "TypeError: Cannot set properties of underfined"

The same message is produced when trying to hardcode in the values with the given example in article: https://api.daypilot.org/daypilot-scheduler-update/

Code snippet

  async updateCalendar() {
    let updatedResources = await this.getRefreshedResources();
    this.resources = unwrapResource(updatedResources);
    let updatedEvents = await this.getRefreshedEvents();
    this.events = unwrapEvent(updatedEvents);
    //this.dp.resources = this.resources;  <---This line failes
    this.dp.resources = [ {name: 'Core', id: 'a1x3J000000lTDQQA2'},{name: 'Cafe', id: 'a1x3J000000lTDRQA2'},];  //  <--This line also failes
    this.dp.events.list = this.events;  //<--This line will also fail if the resource line is commented out with the same error
    this.dp.update();
  }

Do the resources/events need to be cleared before re-initializing?