First time posting so be gentle

I have configured a Raspberry Pi 3b as a torrent box running openvpn and an external drive and have chosen Deluge as my torrent client of choice. When I run deluge-web everything is as it should be until we reach the downloading stage where I note that I have either ridiculously slow download speeds (minus 1.5mpbs) or no speed at all (the torrent starts then counts itself back to 0kbps) even on torrents that have hundreds of thousands of seeders. I've also noted that by adding multiple torrents the client then splits the speed equally between them.
To make sure that this wasn't just a slow VPN I have tested this with 2 seperate providers and have also done a speed test which returns with a more than adequate figures in the 30-50mbps. I have also setup the VPN's to autorun when the Rpi stars.
Concerned that this may be the RPi 3b I have also tested this on another RPi but I get the same results.
I have also looked back through some old posts and have even installed LTconfig and have placed it on high-performance.
If it helps this is the guide I used to setup the torrent box: https://techwiztime.com/article/best-ra ... orrentbox/
I'm pulling my hair out trying to work out what it is that I have either done wrong or why this won't work.
Any help would be massively appreciated.