OK I got it.
In version 5.2.5 if there is an ACF field somewhere is the site, EVEN if it doesn’t apply to the page with location rules, it will return that empty string var.
E.g. I had in a template get_field(‘test123’) which returned NULL.
I then created an ACF field called test123 but made the location rules so that it definitely didn’t apply to the page i was testing on.
I refreshed the page and it then returned an empty string var.
Hope this makes sense….
