A bit of troubleshooting, but no firm solution yet. Here's what it looks like it is related to:
https://www.mediawiki.org/wiki/Manua..._text_is_there
Updating to a version of PHP that is reasonably secure, ends up with some ancillary software that isn't compatible with the version of MediaWiki I need to run to integrate with vBulletin. When I have some more time to tweak, I will see if I can downgrade just some necessary PHP components to see if it fixes the issue. It's a bit of a sticky conundrum.