Ubuntu 18.04 is up to date. On Firefox, browsing seems to spend all of its time "looking up xyz". Ubuntu 16.04 was much better. On the same hardware using Fedora 28 and Firefox, the web browsing time is excellent.
Tried Chrome, worked great. Reloaded Firefox, same results. Firefox version: Quantum 64.0 Mozilla Firefox for Ubuntu. Canonical - 1.0.
Tried using DNS servers Google and openDNS. Not much help.
I am using x86_64, 4.4 GHz clock, 16 GB memory, SSD drives, 60 Mbit internet connection.
Until this gets fixed, I will have to use Fedora.