One site down for no obvious reason

We have one website on our MULTISITE having problems.

The master site is: hosted on Cloudways.

All of the sites are loading such as these for example:

The ONE and only site that is not loading (since this morning) is this one:

I have granted support access... Please help, this is urgent and we have exhausted everything we know to try, have restarted services on the server and had cloudways support restart server also.