Looking at your code over there, the biggest thing that I see when it comes to ACF is that you’re using the field name when updating the ACF fields.
When a post and the ACF field values does not previously exist, using update_field() using the field name will fail because ACF does not know what to do with the value.
When using update_field() in this situation you need to use the field key instead of the field name.
You could also use update_post_meta() and add everything that ACF will need. When ACF adds a value to the field it inserts 2 rows in the database:
meta_key | meta_value
{$field_name} | $value
_{$field_name} | $field_key
