Kula-shreshta-yoga
Kula-shreshta-yoga is formed by Venus and Saturn when they occupy their own signs. This combination makes a person obedient and devoted.
Shri Govind Swarup Agarwal - "Vedic Astrology"

In which cases do planetary yogas not bring expected results
In order for a yoga to be activated and work, certain conditions must be met: it should not be spoiled by malefic planets; and the Sun and Moon must be strong enough in the horoscope.