Can you elaborate what steps lead to 10-20 sec delay?

I've a new computer (with Windows 10 - like my old one) and now everything goes much quicker, but only the tagging goes very, very slow. It takes 10 or 20 seconds to get the complete info and after that changing also takes much time.

When I put in a artist I don't get a folder with possible names, only one when there's only one possibility.