At one point I tried to set the router vpn client to use GCM and couldn't get it to connect. Could have been user error. I know that the PIA Android app now supports GCM. With the 5/22/2018 version of PIA's windows client under data encryption they offer AES-128 and AES-256 with no mention of CBC or GCM and then for Data Authentication they offer SHA1 and SHA256. On the Android app when selecting one of the GCM encryption methods the data authentication can no longer be changed and states "AEAD ciphers like AES-GCM use an integrated authentication mechanism. This leads me to believe that they are not using GCM with the Windows client. I factory reset after updating to 384.5 and have not setup the vpn client again. Perhaps I'll give it another shot.