Websites generally don’t disappear on their own. And I’m not aware of any hosting issues that could have anything to do with this.
Are you sure you successfully transferred your entire website from your local backup to your hosting account? Because it seems like the database hasn’t been transferred at all.
Please make sure to transfer your files and your database when migrating your website:
And please note that if you install a site with Softaculous, you get a completely new, empty site. So if you’re looking to migrate an existing website in, you probably don’t want to install a new site with Softaculous.
Premium hosting does include free migration assistance and one-on-one customer support. But premium staff doesn’t have access to your local computer, so they can’t migrate your website from your own computer to your hosting account either. The only thing they can do is basically tell you what I just told you.