There are sometimes issues with routing to the Itch file servers.
The alternative download buttons did not work?
Depending on location, it can happen that the routing is bad. You might want to try a vpn. If you have no vpn, try using Opera's built in vpn.
There are some threads that have this topic, but it usually is a whole area that is temporary blocked off. But maybe it is a different issue in your case. I think the error messages were also different.
Maybe a network outage routed traffic over a location that could not access the servers.