The Problem
VPN speeds are significantly decreased despite trying to account for all variables I can think of. Significantly decreased in this case means that absolute best I can temporarily get is 250/250 out of my 500/500 connection as measured with iperf3. However, "real life" use with bittorrent and usenet is much slower. i have consistently had a max upload speed of less than 500 kB/s with transmission. downloading from usenet which normally can max out my connection is stuck at 5 to 6 MB/s (it's about 60 MB/s on same device and network w/o VPN ie ~ 480 mbps on my 500 plan). I am absolutely stumped, any advice is very much appreciated.
Steps I have taken
Confirmed expected speed w/ iperf3 when vpn is disconnected. I tested between local machines, with remote public iperf3 servers, and between iperf3 docker container and remote public iperf3 servers (~ 1 gbps locally on gigabit ports, and ~500/500 mbps externally with my 500/500 plan as expected both directly on host and in docker). i also tested with iperf3 in gluetun container with vpn activated (best result was 180/150, most much lower)
Tried different servers in different geographical regions, including my home country
Tried OpenVPN vs Wireguard
Tried using specific ports like 53 to bypass potential ISP throttling
Tried TCP only for same reasons
Disabled all ipv6
Tried adjusting MTU for wireguard
Tried LSIO wireguard docker image, gluetun docker image, and regular (non-docker) wg
Tried with and without VPN port forwarding (with gluetun)
disabled UFW because at this point, why not right?
Tried all of the above with several different VPN providers (Proton, OVPN, AirVPN) and spun up my own wireguard vpn server on two different VPS providers with same result
I have swapped out my older router with a brand new one since the 500/500 is an upgrade from my previous 250/~25 connection and I have many devices connected. I got a slight improvement from 450 mbps down without VPN to 500+. No discernible improvement with VPN connection.
Suspecting potential VPN throttling from my new ISP, I have even got a second ISP to try things with. both are 500/500 and provide speeds as advertised.
i even tried gluetun on a different computer. the second computer i tried had 11th gen i9 with 32gb ram and was debian 11 (from an older PC running current LTS ubuntu server). same issue
Since everything is "working" (successful tunnel connection), I have no idea what I can provide in terms of logs or whatever to help resolve this.