Autosave function buggy?

Hi forum, we have version 11.10.10 of xwiki running.
When a user use the CKEditor and the autosave function, under the history tab the versions number will count forward, but the content of the page itself will be the same.

So when the user is typing and he close the browser(or it crash), then not the last auto save version is shown. When the user open the page in the edit mode again, then he will see the version before starting editing. And all changes that was doing in the auto save states are lost.

Is this an bug, or how will auto save will work in detail?