Cloud Sync Task freaze

Hi,

I created a cloud sync task to upload .jpg files to S3. This task is programed to run once time at the day. 

But when starts to run, the task freaze at any point of the progress sometimes at 1%, 5%, 3%, 25%, etc. Only just one time the task compleated at 100% succesfully. So I need to stop the task completed and run it again. 

Any sugestion?