Put your saddle back to the original height and lower it 1 cm at a time. Big changes are not good for the body. Those formulas get you "in the ballpark". They are not meant to be exact for everyone. Everyone is different and flexibility, pedalling style are variable for everyone.

The ball of your foot should be right over the pedal axle. Your leg extension at about 7 o'clock is maximum extension. At that point, your leg should still have a comfortable, slight bend at the knee.

Remember, just because you cannot feel your hips rocking doesn't mean they aren't! You need someone to look at you pedal to see if your hips stay level.