I set this server up (we're on dedicated hosting), and I don't believe I configured any cache on the server, but I'll check. I only run apache. Don't want to learn yet another app.

The Stovebolt Geek
https://www.stovebolt.com/ubbthreads/ubbthreads.php

Server Information
UBB.threads Version 8.0.0
Release 20240826
Server OS Linux
Server Load 0.11
Web Server Apache/2.4.37
PHP Version 8.3.11
MYSQL Version 8.0.39
Database Size 1.82 GB