Select SAUTE setting on a programmable pressure multicooker (such as Instant Pot). Select HIGH temperature setting and allow to preheat. Add bacon to cooker; cook, stirring often, until crisp, about 6 minutes. Transfer bacon to a plate using a slotted spoon. Add leek and bell pepper to drippings in cooker; cook, stirring often, until slightly softened, 4 to 5 minutes. Add corn, potato, butter, salt, and cayenne; stir until butter melts. Add flour; stir to combine. Add water, and stir to combine.