Website downtime fix

We have a wordpress website, which uses Cloudflare, and are having periods of 5-10 minutes offline (http timeouts) before it comes back online:

- When the site goes offline, it is still offline when you switch off Cloudflare.

- When you switch off cloudflare, also the static html pages dont load

- Another site on the same package of server (i think the same server) has not experienced this downtime

- The website has country versions hosted on a different server via a plugin, they are also down.

If someone is experienced in server setups, maybe DNS issues, and can suggest what could be done i'm happy for them to take a look.