[2020] Report player downvoting map

Hello, so after 1 month of a great new experience on this game, finally met the first toxic player. The guy voted 1/5 on every map during map review on purpose. HIs name was Timek2502 (or Tymek and not sure about the number) and has the polish flag). So I did my first and I hope last report but I wonder, how does report works ? Is it better to do it IG or in the forum ? Is it usefull or is it just a feature ?