Synch deletes local folders?

I wanted to synchronize some folders from my local macbook to the MyCloud Home Duo. Synch worked well, but now my local folders are empty. All data seems to be transferred to the MyCloud Home Duo and were deleted on my macbook. Ist that right?
I would prefer to have a copy of my data on MyCloud Home Duo instead, which is always updated when I change any things on my macbook.
How can I do so?
Thanks for your help…

You may want to see the dedicated My Cloud Home Duo subforum. This subforum is generally for the single bay, single drive My Cloud which is different than the Home line of devices.

You may also want to see if there are similar issues or discussions in the dedicated WD Software subforum. One can use the forum search feature, magnifying glass icon upper right, to see if there are past similar discussions.