Before your cPanel EA3 to EA4 upgrade, have you switched back to Apache? It is a must. If the answer is yes, then it may have broken something.
Try to use script to switch over between apache and litespeed a few times then test again to see if it helps
/usr/local/lsws/admin/misc/cp_switch_ws.sh apache
/usr/local/lsws/admin/misc/cp_switch_ws.sh lsws
If problem persists, Please log a ticket in our system with tmp root access. we will have a further investigation.