Then successfully configured transmission to work through it.
I got greedy and after successfully running it for 2 weeks, I installed then uninstalled pi-hole.
After uninstalling pi-hole everything went to crap. I reverted the actual router settings to automatically use DNS from the ISP. However, the Pi can't resolve DNS. I've tried changing the resolv.conf to both what the guide originally had (127.0.0.53) as well as my router IP.
Any suggestions on how to diagnose what is going on?