It seems that the post content and title in v4 are not available to front end forms by default.
However, Jakes answer in this Stack Exchange question fixes that… http://wordpress.stackexchange.com/questions/9912/front-end-post-editing-using-a-form
Anyway, this works for v4 – I have no idea how v5 may do this. Maybe the author can advise?
Also why cant I find any documentation on the acf function register_field_group ??
