Painfully slow when adding media via WebDAV

I’m not sure if others have/are experiencing this but when I add all my media into Infuse via WebDAV (using Synology NAS) and is extremely painfully slow. Adding by Emby or Plex server is a tad slow but absolutely nothing like WebDAV. Any reason why?

What do you mean by add into Infuse? Having it indexed?

By my experience, every time I loads the webdav folder content is painfully slow on Infuse. But no issue on playing, it’s very quick.