already apt-get install lws php 8.1 manually and success
change website to 8.1 no error
edit php 8.1 config no error
restart php no errpr
restart litespeed
open website with 8.1 (wordpress) result = error. critical
I haven’t tried using lws php 8.1 so don’t know if it’s a problem with that itself, but that’s WP error page, so it could also be that one of the plugins on that site is not compatible with 8.1.
Try a new clean WordPress install and see if that throws an error or works ok.