Hello!
I honestly don't know how any client for Itch handles the game. The builds are uploaded in a dropbox and Itch redirects you to the download links, so it is needed the users to download the files and execute them by themselves. If that client installs and/or executes the game by itself, I don't know how it does that.
Maybe you can try downloading the game in other way to see if you're having another problem.
I wish you a good day.
~Krosbar