Experiencing same bug in latest version.
CLOUDLINUX 6.9 standard WHM v68.0.19
To fix it I edited:
/usr/local/lsws/admin/html.5.2.2/classes/ws/STATS.php
found the line:
if (strpos($_SERVER['LS_PLATFORM'], 'freebsd') !== FALSE) {
and basically just disabled the if to always return...