If you have purchased the PRO service of your site with DNS Service and therefore the domain you are using has been registered with a third party provider, it is possible that the DNS configuration has not been performed correctly.
I remind you that the DNS configuration of your domain must contain all the records indicated in our guide Setting DNS Records, and that the reconnection problem is often caused by an error in the A Record or in the CNAME.
You can check for DNS pointing errors by opening a new tab and looking for your domain with and without www (i.e. you will need to search for your domain such as mariorossi.com and www.mariorossi.com).
To check the current configuration of your DNS records, you can PING the domain using your pc's Command Prompt or using an online service such as https://pingtool.org/
To check on the online service that the dns records are correct, you will need to enter the name of your domain in the Target IP / Hostname field (for example mariorossi.com) and then repeat the operation by entering the name of your domain including www. (for example www.mariorossi.com)
In both cases, the IP address of the Record must be 35.190.27.135, as shown in the two images.
If you encounter a different IP address on at least one of the two hostnames, you will need to reconfigure the DNS records by accessing the DNS configuration panel of your current provider. All the configuration parameters are present in our guide.