Websites Not loading

I have installed cyberpanel in my droplet in digitaloccean.
After that I have added few websites to it. Everything was working fine till yesterday and suddenly the websites added in cyberpanel stopped working.

https://www.companiesonsale.com/
https://www.digitalledscreen.com/

I dont know the issue.

Restart your server and see.

Your server or DNS server or web-server is not running.

I have done that many times.
But no use.

I have other websites loading without any errors in the same server:

http://maqcart.com/

You can send login details privately. I will have a check and guide you solution.

PM sent.
But its horrible.
So I shifted two of my websites to new droplet.