MVP means minimal viable product. “Minimal” leaves room for ambiguity, admittedly – but not much.
The reality is, making the product work isn’t what investors care about – they care that the working product has a market.
Ergo, pragmatically, an MVP should be the lowest possible viable product that can test and prove the product has a market. If you can’t do that, it doesn’t yet qualify as an MVP. If it can do that, it does qualify as an MVP.
Further and more to the point: if it is an MVP and can’t find a market fit, that doesn’t normally mean it needs more features. It means it’s a product looking for a market, unfortunately.
The #1 rule in startups: fail fast, people.