Server cannot connect anymore

I have install litespeed using this Link I didn't point any DNS as it is still in develop, I'm hosting in AWS Lightsail with ubuntu platform, but around today (i,e,. 19th Oct 2021) 12:00 noon I cannot access my site it showing
This site can’t be reached
<IP> took too long to respond.

I reboot, stop & start lightsail instance but cannot get running, I can connect using Lightsail instance SSH but not from local (using .pem file I have download)

I'm not sure whether is this lightspeed error or server

I'll be appreciated if any helps, thanks in advance
Last edited: