By default shortcodes in acf textareas are not rendered, so you’ve already got some filter in place.
I’ll asume that you use the filter 'acf/format_value/type=textarea'
If you use the do_shorctode function or apply the_content filter inside without restricting it to the frontend only, then your shortcodes would be rendered in the admin textarea fields as well.
To prevent this try to add the following restriction
if (is_admin()) {
return $value;
}
So your filter for acf textareas may look like this
function process_acf_textarea( $value, $post_id, $field ) {
if (is_admin()) {
return $value;
}
return do_shortcode($value);
}
add_filter('acf/load_value/type=textarea', 'process_acf_textarea', 10, 3);