Hey Alain,
I wish I could help with internet issues, but that is outside my ability. I would recommend checking your firewall/browser settings.
After that, can you try downloading the free version over on our Patreon to see if we can isolate it being an Itch issue?
https://www.patreon.com/posts/0-7-8-free-107880621?utm_medium=clipboard_copy&utm...
Much appreciated for understanding.