Since the last updates of Chrome, I can't access to an offline page even if the cache.manifest is correctly "installed" (I checked chrome://appcache-internals).
I also checked if the system worked on iOS and Android (Chrome) devices, it works fine...
So, can you confirm (or not) that it is a Chrome (desktop) bug ?
Edit :
When I visit the page, I see the logs of cache.manifest loadings... all succeed. Just after, if I visit chrome://appcache-internals, the cache.manifest is in the list. But, if I go back to the site, toggle chrome to offline mode then reload, the message "no connection" is showed.