Right, that makes sense if you can’t adjust your router’s DNS. However, you can manually change the IP address of the DNS servers you want to use per device. I recommend trying to change the DNS on your computer or something to your pi-hole’s IP address. If you do that and can get internet access you should be good. If not then you can check the pi-hole logs to see if it’s getting any of the DNS queries. Feel free to DM me for more help.
Maybe something like this? https://grafana.com/grafana/dashboards/15116-qbittorrent-dashboard/