You are kind, Guust. Thank you for taking the time to look at that.
I learned something — will pass it on to someone else who might be distressed by the disappearance of the WordPress standard custom fields.
You were 100% right…it WAS/IS a plugin…Advanced Custom Fields. This is not the FAULT of ACF, it is the INTENT. Apparently, the plugin is to take the PLACE of WordPress’s own custom fields.
“Advanced Custom Fields (ACF) is a free WordPress plugin that replaces the regular custom fields interface in WordPress…”
I didn’t realize it because I’ve never tried to use ACF at the same time as I used WordPress’s standard custom fields. A learning experience.
I determined this more easily than I had thought — using the marvelous plugin: Health Check with its trouble-shooting abilities. Really a useful tool for a developer’s toolbox.
With Health Check, I can easily turn off ACF, go into Home Page, change the Subtitle custom field (Supreme Theme) then turn ACF back on for other use I have for it.
But…I wonder. Is there some kind of filter I could use for the Subtitle so I could put a subtitle custom field into ACF and use it in the filter?
As I said, with Health Check I have a perfectly viable workaround. Just wondered about the filter.
Thanks again for giving me a pointer as to where to look. It pointed true!