PDO - Query returning 0 results but returns results in phpAdmin

Question

I am running the following query below, returning 0 results in my PHP. However, when I paste the exact query into MySQL and copy in the relevant values, I return the results that I desire.

So, why is my query below returning 0 results?

$get_markers = $pdo->prepare("SELECT tbl_jobs.job_id, tbl_jobs.job_lat, tbl_jobs.job_lng FROM tbl_jobs WHERE (CASE WHEN :swlat < :nelat THEN tbl_jobs.job_lat BETWEEN :swlat AND :nelat ELSE tbl_jobs.job_lat BETWEEN :nelat AND :swlat END) AND (CASE WHEN :swlng < :nelng THEN tbl_jobs.job_lng BETWEEN :swlng AND :nelng ELSE tbl_jobs.job_lng BETWEEN :nelng AND :swlng END)");

$get_markers->bindparam(":nelng", $nelng);
$get_markers->bindparam(":swlng", $swlng);
$get_markers->bindparam(":swlat", $swlat);
$get_markers->bindparam(":nelat", $nelat);

$get_markers->execute();