Finder slow to show new files created.

Since High Sierra, i have a problem: When i download a file or extract files from a zip/rar-file, it takes everytime about 10 seconds to see the new file(s) in finder. why is it so slow? what can i do? it is a waste of time everytime this happens.

I already made all optimizations discussed in other threads (removed Recents, disabled Spotlight on every folder except for Applications, used a file list view for faster rendering) but the problem is still here.