Stop nextcloud to create local copies

Hi,

I´m using the latest Nextcloud version with different group folders. At my group folders there is one master, which uploads the files from a windows machine and other clients (also windows) can only read / download this files at their clients. It happens at my master upload machine that nextcloud creates local copies of some files (conflicted copies called). How can I stop nextcloud for general to create conflicted local copies and set that local files always have priority?

This conflicted copy files rises and I need to stop this. I hope, that somebody can help me out.

Thanks!