I think this is still an issue for Options pages.
Niether true/false or 1/0 produce any results.
For anyone interested, here is a return function that will work with ID by default or options:
function custom_get_acf_boolean($field, $location = "ID") {
$location = $location === "options" ? "options" : get_the_id();
$field = get_field($field, $location);
return $field ? "1" : "0";
}
Then use == or !=
with 1 or 0