Cross-pollinating plants often produces a lower tier that that of the parents. That's why you need to keep track of your breeding or carefully follow one of the breeding charts in the guide section. The Ananas and Maple you crossed should have produced a Jalapa Lemonbush. Maybe you didn't select the plants you thought you did. Crossing a Jalapa Maranta and a Citrus Ball Cactus will give you a Four-petal Maple.