Failure of iPhone (16 pro max) images to upload to Lightroom Classic

iPhone images are not uploading to Lightroom Classic. First, the newest images did not appear together. The queue was completely out of order. Now, no images appear at all. Just blanks. In trying to solve it, I read about sync option, thinking maybe I should do that. But sync never ended, seemed to get stuck. Now, sync window says "Sync download location is not accessible." I've paused syncing. Am lost at this point. Thanks for your help. L Gracey