DNS failure to resolve after turning on VPN

Hi guys im over ubuntu artful, installed from apt packages i can login i can turn on vpn after that i cannot resolve domain names

i attach the bitmaskd.log

bitmaskd.log

if a ping a domain i get "temporary failure in name resolution"

i tried with automatic dns servers from ISP, with google and with openDNS servers and all the same.

hope this helps

thanks for the great work!