Okay, so tinkering around again I moved it outside the connect() function and it works!!! No more posting and no more adding random events. So my text above for the code is correct, just move

  closeModal(event) {
    event.preventDefault();
    this.modalTarget.removeAttribute("style")
    //_this.modalTarget.style.display = "none"
  }

 to below 

calendar.render() 
}

Make sure its after the } so its outside the loop.