Comment by pogue
You definitely want to be following yokoffing's NextDNS Configuration Guide [1] to set it up. You basically only want to be using one of the Hagezi blocklists [2] and a possibly a few other options based on your preferences.
I have it running on every device in my household and it works absolutely fine. I keep it on Hagezi Pro++, and that requires me to go through and whitelist some sites I use. That can be annoying, so in that case Hagezi Light or Normal should work just fine to block ads/trackers and not break things you have to go in and manually fix.
OTOH, Control D offers free DNS [3] that includes using the Hagezi blocklists and other lists, but it's just a set and forget type setup as you can't look at log files to see if it's blocking stuff you don't want or anything like that. Scroll down to "3rd Party Filters" to see their offerings.
[1] https://github.com/yokoffing/NextDNS-Config