Sexual reproduction can have bisexual flowers and monoecious plants; Unisexual, monoecious or dioecious. What you see may be unisexual flowers and dioecious plants.
Vegetative propagation belongs to asexual propagation, which refers to the propagation mode that a part of plant vegetative body (branches, leaves and roots) leaves the mother body and develops into a complete plant. For example, willow cuttings are used to plant willow trees, such as rooting, such as bamboo shoots, such as bananas, such as potatoes, and sweet potatoes are thrown into the ground.
Therefore, although the plants you see bloom, they probably don't have reproductive function, but reproduce through vegetative bodies.