It worked John! Thanks a lot for all the help, I’ve been troubleshooting this for over a month already.
BTW, can you add the function tag to that function, just in case someone wants to copy and paste the solution?
Looking past what the cache is returning, I would look at what could be causing the get_posts() query to return an empty array, because this is where the empty array in the cache is being set. This has to happen at some point before you see the fields disappear.
Regarding your previous comment, I’m not sure to what line or file are you referring, but the line that’s returning an empty array is not get_posts(), it’s this one:
$post_ids = wp_cache_get( $cache_key, 'acf' );
