So this is definetely a bug.
Please try it out. Go to the startpage https://itch.io and search for any tag or game.
It will display exactly a maximum of 60 games and ignores all the others.
Just if you continue and click the tag button it will find all games!
But that's not how a search in 2019 should be!
The support says everything is allright, but it's not!
So how to talk with a wall? ^^ It's realy annoying.