curious have you tried to set dns rebinding protection off both on the router and on nextdns itself?

also, are you using different subnets on some devices?

I was just playing around with a streaming app on tv, and figured out that there was a blacklisted domain from google in nextdns which made the streaming a black screen something with imasdk do you see that sub domain popup maybe in nextdns logs from google?

as for advice, I’m not certain yet.