Possibly. There seems to be a hard cap at 3Mb and about 2-2.5 on upload. I dont have vLans setup though, but I too cannot find anything in the logs that would give a clue as to where the restriction is. Its very odd… I am not running the proxy in transparent mode as I have a .pac file that points systems to the proxy. I have tried running in transparent mode by manually setting a client PC to pfsense as the gateway, and the problem goes away. Since I will eventually replace my original firewalls with the pfsense ones, this will be a non-issue soon.