SYNC does work well?

I would like to synchronize all folders from my local drive (for full information I’m using Win10 on macbook pro) to my MyCloud Home Duo. Synch seems to work! All data are copyed to the MyCloud Home Duo, but sometimes my local folders are empty. After some hours local folders show all the files again. Is that right? I do not think this is a correct behavior. I would like that data on my local disk to never be changed.
How can I do it?

@Bruno03

https://community.wd.com/c/home-cloud-storage/my-cloud-home-duo

Apps for My Cloud Home Duo.
http://www.mycloud.com/#/apps_os4

http://learn.mycloud.com/