YouTube not working via SSH tunnel proxy to a U.S.-based IP address

YouTube is blocked in my country. To connect to this site, I created a SOCKS5 SSH Tunnel proxy using this command and configured Firefox accordingly; 111.222.333.444 is a U.S.-based IP address:

ssh -D localproxy:9999 -C [email protected]

It connects and works well. I can Google “My IP” and I get 111.222.333.444 which means connection is working.

But still, no luck with YouTube. It won’t connect to it despite the proxy to a U.S.-based IP address.

As far as I know some countries manipulate with DNS table. By default Firefox uses regular DNS - not the proxy one. Go to about:config and set network.proxy.socks_remote_dns = true.