NextDNS not working for Apple devices but works on every other device

Hello,

I'm a paid NextDNS customer and I have NextDNS configured on my router. On every other device other than my Mac, iPhone and iPad, visiting test.nextdns.io shows status OK. It only works if I set the DNS manually on each Apple device, but that defeats the purpose of setting up the router so that I don't have to deal with each device manually. I don't have Private Relay turned on, and yes, visiting my.nextdns.io shows "All good!". What should I do to mitigate this problem. I'd really like if I didn't have to configure DNS manually on all my devices.