Disable query rate-limiting on Pi-Hole to fix DNS

Sometimes DNS issues in Pi-Hole are a result of the DNS query rate-limiting enabled by default, which can be disabled altogether by editing a single file.

Credits to this post on the official Pi-Hole blog and this post by u/Thom__Cat in r/pihole Subreddit

Edit the FTL config file:

sudo nano /etc/pihole/pihole-FTL.conf

Change the line for rate-limiting:

RATE_LIMIT=0/0

This solved random DNS errors I was having after I getting several rate-limiting warnings in Pi-Hole diagnosis.