They are reporting "family daily active users" and I assume that this "family" means all of their apps. They are reporting 3.56 billion DAU, but Whatsapp alone has 3.3 billion users according to some sources. So we really do not know how Facebook or Instagram are doing from those numbers - and it does make sense that user numbers are dropping when Russia is restricting access to WhatsApp & Co and Iran is switching off its internet.