I also get this periodically on WiFi and data.

@boogetyboo there's still a good chance you're using your Internet Service Provider's DNS.

Not only does this mean its super trivial for them to block things they don't want you to access, but this also means they can see (and they probably log) everything you do; no good for privacy or freely accessible info

Try switching to something like quad9, and reboot your devices after to make sure they've cleared their DNS cache

PS:
You can just add dns.quad9.net to Settings > Network > Private DNS on Android if you don't want the app.