According to some geomantic theories, the master bedroom door should not be too big, because it is auspicious to gather wind and gas, while the second bedroom door should not be too strict relative to the master bedroom door, so the master bedroom door is lower than the second bedroom door to form a better geomantic pattern. However, this is not a universal law, because the layout of Feng Shui will be affected by many factors, such as the specific structure, orientation and life of family members.
Generally speaking, the height of the bedroom door should be determined according to the actual situation and personal preferences, and it is not necessary to be too rigid in Feng Shui theory. If you are really worried about Feng Shui, it is recommended to consult a professional Feng Shui master or interior designer for more accurate advice.