All vesions of opera below 49.0.2725.64 with VPN/On opera killed the vpn.. also the older version did not require Port 8000
The newer Opera's 49.0.2725.64 version And on up with Vpn/ON Are the only Ones that have opera's VPN currently Working..
Note all newer version require Port 8000 outbound to be open..
and since ya said you looked and nothing has changed then maybe firewall or anti-anything could be blocking port 8000..
if you installed opera 49.0.2725.47 or older vpn has been killed but turbo does still work.. i think lol