@tada
You called it, man: Outdated third-party plugin that I wasn’t aware had ceased running updated because the original support license expired.
In this particular case, it was Events Plus from CodeCanyon
I even went as far as to disable the plugin to see the issue go away, then reactivate it to see the problem come back.
I pulled out the older version, got the latest one and now everything is working together fine. Thanks for your help.
@tada
The 1-by-1 plugin attack is actually my next step. I thought I’d try here first with you guys to see if a specific plugin, or some other issue, jumped out at anybody. I’ll start down that road first thing tomorrow if I don’t come across any other ideas here. Thanks for your input.