Hello,
Thank you for reaching out and I am happy to assist you with this.
 I’ve checked the website and as I can see on the first load, the proxy and server cache are active:
 x-proxy-cache: HIT
 x-server-cache: true
This means that you also need to purge the proxy and server cache. When the page is reloaded those headers are gone.
 x-server-cache: false
 You can confirm this by temporarily disabling the W3 Total Cache.
Let me know if this helps!
Thanks!