It seems odd that in Pro Forms and the Edit Post option that the Update Post Action you need the double curly braces but in the Update Post Meta action you don’t. I can’t see a reason for it, and with th FX button automatically inserting thes braces, it’s just a pain to have to delete them, or as I keep doing, forget to remove them.
Anyway, just a useability issue, nothing too important.
I managed to get the Radio options updating using the ACF array as per the attached. I can’t however get it to show the current option without the Dynamic Shortcodes as you used.
Regards
Pete