or change the DNS Server entry on the Router/Firewall from your ISP (Provider).
have my own DNS Server and had to clear/update the resolver cache today.
anything works fine since then.
and God send you a DNS Server to replace the hosts.
the subnet mask devides the ip-adress in net-part and host-part.
192.168.0.0 /24 = 255.255.255.0 (Privat IP-Range)
192.168.0 is the net-part
.1 - .254 is the host part
https://www.pluralsight.com/blog/it-ops/practical-routing-and-subnetting
DNS-over-TLS (DoT)
DNS-over-HTTPS (DoH)
https://dnsprivacy.org/wiki/display/DP/DNS+Privacy+Public+Resolvers