Updated the Topic Prefixes addon this morning to 3.2.0 and the whole site crashed as it was activating. So I accessed via SFTP and temporarily renamed that plugin, then cleared the server caches. That resulted in the site immediately working again. Checking the error logs, there's no definitive answer that seems to show why this happened, but I'm also not super savvy with error logs either.
wpForo 2.1.7
WordPress 6.2
PHP 8.0.28
MySQL 8.0.32-24