This was the issue in the end, it wasn’t the lack of a post ID, but had multiple. A reset fixed all issues.
… the Post ID seems to be the issue.
I’ll have to figure that one out.
But seems unrelated to the ACF plugin.
I can display the custom field on the page with the ACF option for my text element.
-> this will display 15, hence my conclusion that the field has the correct value.
But I can’t use that ACF option of the text element to put that value as a parameter on the shortcode.=> As in I can’t print/echo the id into the actual shortcode, if this would be the shortcode [shortcode id=”?”], then I can’t get the ACF value on the ? as I can only get that with the text element (which is a shortcode itself).
So I need to get the field via the page id within the shordcode code.
var_dump gives me: NULL
Yes, the name is correct – I checked. I always copy-paste values like this – exactly to prevent typos of this kind.