Brand new install painfully slow

I've just installed the latest FreePBX distro on a KVM virtual machine. The machine is fine. Shell commands are fine. However everything from the FreePBX interface is painfully slow. It's not a browser issue; when I hit UCP (whihc I have yet to see run) it spins and eventually errors out with "maximum execution time of 30 seconds exceeded for Jshrink/minifier.php.

I've turned off the firewall and adaptive firewall. I can ping the world OK. My /etc/resolv.conf is here:

nameserver 127.0.0.1
nameserver 8.8.8.8
nameserver 74.201.43.41

I have tried it with and without 127.0.0.1

Most shell activity is fine, but I notice when I log in there is a long delay while stuff is going on in the background.

I have updated all my modules, and done a yum update (the one through the FreePBX GUI failed). Roughly half the things I try through the FreePBX interface fail because they time out.

I'm thinking it must be something simple, but as this is a fresh install (I've re-installed it several times to be sure), I don't know what it could be.

My container has 4 vcores and 2G of RAM. HTOP shows the RAM is not fully consumed, but system load goes high (10+) when running commands from the FreePBX web ui.

Any ideas would be appreciated.