Well, even if you
vape 1ml in a single sitting, and the entire ml ends up as additional liquid in the air, that seems like an awfully small percentage. I don't know how many ml of water is suspended in the air in your room/house, but I would guess it's considerably more than 1 ml, at least 1L (again, complete conjecture).
Are you sure that turning off the dehumidifier for half an hour isn't what caused the relative humidity to increase so much?