Jackky

I’m not quite sure about my solution, but this did the trick for me:

protected function getUploadDir($field)
{
  if ($this->_uploadDir === null) {
      $this->_uploadDir = wp_upload_dir(date('Y/m', time()));
  }
  return is_array($this->_uploadDir) && array_key_exists($field, $this->_uploadDir) ? trailingslashit( $this->_uploadDir[$field] ) : null;
}

Just wrapping up the return of upload dir with trailingslashit func in the file plugins/auto-upload-images/src/ImageUploader.php

@kloon thanks, that works perfectly