Hello,
You added custom code to hide the rows
.vc_row.wpb_row.vc_row-fluid.mpc-row {
display: none;
}
https://gyazo.com/1e25bb42397c3d9a7c6b3497fc8906cb
That’s why your page is empty when you check it.
I moved the custom code from customizer to child theme style.css, it will be easier for you in future to find out if your custom code is the reason of the problem just switching between parent and child theme.
Regards