ACF -> Crashes WooCommerce – Custom Fields

I haven’t done much programming in the last few years..
although I don’t remember having any problems with other plugins in the past like Events Manager.

New to Woocommerce… been trying to do some things.. for example..
pushing Custom Fields to an email, after an order is completed “customer-completed-order.php”

function wc_email_before_order_table( $order ) {
$provider = get_post_meta( $order->get_id(),'tracking_provider',true);
$number = get_post_meta( $order->get_id(),'tracking_number',true);
echo '<p>Your item has been shipped! Here are your tracking details</p>';
echo sprintf( __( '<p>Tracking Provider: %s</p>', 'woocommerce' ), $provider );
echo sprintf( __( '<p>Tracking Number: %s</p>', 'woocommerce' ), $number );
echo '<p><a href="track.brightledshoes.com">Click This Link To Track Your Package</a></p>';
}

Applying ACF plugin… and setting up the custom fields listed above…
It is a fail at sending the fields to the email.

AFter hours and hours of reading… I found no direct answer… except this code snippet applied to theme’s function.php… turns off blocking of the “regular” custom fields, and I have success.
add_filter('acf/settings/remove_wp_meta_box', '__return_false');

This just doesn’t seem correct to need to apply the above filter.
How, or what, am I doing wrong in my original first snippet above that I can not use ACF without turning off what appears to be a core setup in ACF.

please don’t direct me to a paid plugin…
Thanks in advance.