One thing I have figured it out is, I can access all the related links of the domain on www version of the website. For Example -www.example.com/about [200OK - HTTP Response]
Except the Homepage, that’s the index file on www only i.e. 404 Not found
If the DNS records are accessible with ping, then the problem is in the webserver configuration. An alias is missing or you can create a rewrite condition.
If the domain in your post #4 above is the correct domain it is reachable as www.domain.com and domain.com in my browser (Chrome) but ping times out (which makes no sense) that domain is searchable by DNS Checker.
What is the website built on PHP ? WordPress / some other build tool, which webserver how is it proxied?
Domain.com is just an example of my domain and I haven’t used my original domain here.
I am just saying I am unable to access homepage(index.php) on www version of my website and the same homepage is easily accessible on non-www version of my website.
In my opinion, Virtualmin is the best panel that I have tested so far for virtual servers. With one condition, to be left alone and all the changes to be made in the interface. The moment everyone starts making their own changes, without keeping a tracking of them, problems start to occur. The ping timeout proves that there is a rule in the firewall for ICMP requests.