Did you uncheck the killswitch option in pia?
after you've disconnect from PIA:1. what does your route table look like? route -n2. what is the configuration of your DNS resolver? cat /etc/resolv.confps: once upon only a couple versions of OpenVPN ago (and a similar number of kernel releases ago), it was necessary to manually replace the default route after shutting down a VPN.
blank resolver config file means DNS non-functional. if you have it, running /etc/openvpn/update-resolv-conf should put things back to rights.