I haven't had good luck with VPN's either ... they are notoriously famous for slowing your internet connection with your ISP, but sometimes mine has shut down too. My last try was with Bitdefender with the random VPN protocol (& paid). With so many devices in the home needing internet access none of the VPN providers can keep up.
My thinking is it's just not ready for prime time. A good solution, but lacking in refinement. I'm now back to strict firewall protection and no VPN until they can get their act together.