I spent at least two hours editing a page only to accidentally click a link to another page and lose all of my work. When I pressed back, all of my changes made were gone. Please try to understand my frustration when I say that I am extremely angry about this, and I am unimpressed that this happened, because a simple pop-up box is all that was needed to prevent it.
What wiki were you on? This might just be a specific feature for certain wikis, but I was on the Villains Fandom. Like I say, I'll just follow the workaround procedure I noted above.
Nope its a Chrome thing (which I know because the message for me is in Dutch which is the language I've selected for Chrome while I run Fandom in English)
Okay, so I just repro'd your issue and it does seem like an oversight by the Visual Editor functionality... I would report it to FANDOM staff via "Contact us".
The legacy Visual Editor really should warn you when trying to navigate away, but it doesn't. If you want to avoid this problem, you should use the Source Editor. They may not want to fix the problem, though, since the Visual Editor in the UCP doesn't seem to have this problem.