I've had this happen to me several times now - and my colleagues in the same organization report they have experienced it as well - writing a long comment on a Confluence page, accidentally navigate away from the page and then the work is ... all gone.
There is a support doc that says that work is "autosaved" and that it appears in drafts either on dashboard or in user profile, but we don't find that to be the case. The documentation is inconsistent though, elsewhere it says you can save the document if you want it to appear in drafts. When I Save then of course I don't lose the work, but that also publishes and notifies people by email.
I've taken to clicking save every few minutes, so my colleagues get spammed during my composing process.
Any suggestions?