Problem solved.
I made a special rule in the firewall for AMC and disabled http traffic scan in the antivirus (didn't know it was enabled). Strangely, it works this way, but with both the firewall and the antivirus turned off it doesn't.
I'm having the same problem for a while, but the solution doesn't work for me. I tried with Sygate off and with Bitdefender off and I still get "Read timeout". Windows firewall is also turned off.