This website is running on VPS from Linode.com . I have configured every single detail about the site, and as you have noticed that the website has only one version with https. I have only peshmerge.io (non-www) version. This morning I have clicked on the link of my website on my twitter profile and what I saw is the default Apache2 page which you get after installing Apache on Ubuntu.
So when I visit http://peshmerge.io it should redirects me to https://peshmerge.io . But that wasn’t the case. I started checking everything on my server. I have checked every line of the configuration file located in /etc/apache2/sites-enabled/mysite.conf It seemed to be correct. Then I have checked the content of .htaccess in my wordpress installation and it was also fine.
After a long research (one hour) I could address the problem. The problem was that my default 000-default.conf file wasn’t disabled. I have disabled it using the following command:
sudo a2dissite 000-default.conf
The problem is solved. But remember if you face the same problem, you have to check first your apache config files or htaccess files.