php_fpm stops with no useful logging - how to troubleshoot?

I'm not looking for someone to solve this for me, at least not yet. I 
want to give this a solid try myself. The problem is I have no 
experience with this level of system troubleshooting; I'm very well 
versed on the network infrastructure side of things, much less so on 
FreeBSD troubleshooting capabilities. So, I'm just looking for guidance 
to get me started, lest I wander for too long in the wrong direction.

I'm running a mail stack (postfix, dovecot, amavsid, roundcube with 
nginx) in a VNET jail on 14.2-p3, and most everything is humming along 
nicely. Once every 2-3 days, the php_fpm process (php version 8.3.20) 
stops and requires a manual restart via `service php_fpm start`. There's 
nothing useful in any logs, and this is where I'm feeling stuck.

Any nudging in the right direction to start troubleshooting would be 
greatly appreciated. I'd like to use this as an opportunity to learn how 
to approach application troubleshooting on FreeBSD, and hopefully be a 
more useful participant in this community in the future.

Cheers
-Justin