I have been using Private Internet Access for 4 months and have their add-on/extension installed in Firefox, Chrome and Vivaldi on multiple desktops, laptops and virtual machines (Linux and Windows). Not sure what issues other users, who complain and give 1 star, have in their specific environments, but for me the PIA VPN service always was and continues to be reliable, and all their add-ons work flawlessly. Sometimes, when not using the browser for a while, the connection may drop. Not a big thing - just disconnect and reconnect again. Very happy with PIA so far and would recommend. 5 stars from me!