dani is correct, you need to be able to express the number as two different sets of two cubes in order to return true.

I may be reading the text wrong, but the number has to be written as the sum of cubes in two ways. n=a^3+b^3=c^3+d^3, where a,b,c,d are positive and different.

From what you are saying, for 46163 you've only managed to find a pair of numbers that satisfy that condition

Same here. Hardcoded, but still an issue.