Perhaps this is a ghost autosave – existing but lacking information about the game? It’s a real autosave that disappeared previously but was later found among other saves, but it no longer contains information about the desired game! Many encounters with such autosaves are obvious fabrications, but there are real cases confirmed by documentation. The reasons for the disappearance or demise of such saves can vary, often with noble intentions – such as striving for the best, for victory! But, of course, most often it’s just simple cheating).