There are 2 similar-looking but different types of these cacti: one genus is Hatiora, which is often called Easter cactus and blooms in spring. The christmas cactus blooms in winter and it is schlumbergera. The flower shapes are different. Yours look healthy and happy and I think the reason cacti don't always bloom is that they need to feel the temperature changes of the seasons. In the house they often don't feel this difference