it's a cPanel issue, not litespeed issue.
how to produce?
"If you login to WHM, scroll to the MySQL section and choose phpmyadmin, select any database and click the import button, you will see next to the file selection (max 105mb)."
so this phpmyadmin is running under cPanel's web server(port :2087), not under litespeed. best to ask cPanel or search for cpanel's forum to get the workaround/solution.
cPanel's web server's signature: cpsrvd/22.214.171.124 (in response header)