Default Boost theme, Php 7.3/4 (dosen't seem to make a difference). APCu, opcache enabled...
Can someone suggest something for me? I don't get why the login page would take forever to load. I've installed the VPL plugin along with Level Up! but that's it. No query errors other than the user-related one I mention above.
Might not be the issue, but APCu is a user PHP cache/accelerator which isn't required to run a Moodle. The typical Moodle install requires/recommends Zend OpCache now, so suggest disabling/unloading that PHP extension, restart your web service, then use the cli script for purging the cache moodle has in admin/cli/
Another instance on same server running under same PHP and PHP config?
You've not mentioned other ... but do you have anything that is a WAF (web application firewall) ... like mod_security or other similar?
To me, 60 seconds suggests a timeout is expiring. For example something configured to call to something via a network connection, but it doesn't hear back from the remote end so after 60s it gives up and continues.
Some things to check: if there are any additional plugins installed? If there are any non-standard authentication methods enabled? if using an additional theme is this configured to do something special for login?
Your browser's developer tools may be able to help (for example: Network Monitor in Firefox) by showing if it's the resource /login/index.php that's taking 60s or something else.
On a CentOS 8 server with 2 GB RAM with no other load I'd expect the login page to load within 2 seconds, with no OPcache, maybe 5 seconds.
If you do see debug info please share it, it may be relevant.