Price doesnt change when i change the size variant and color variant

Good Morning i dont know if im on right place to do this question,but i will do it ,and im sorry if this is not the right place,

I have difficulty to understand where im doing something wrong when i change the size and color variant, i have tested everything and i cant put it work, can the support help me understand better this problem ?

Example : size S and color blue = 23€ / size S and color red= 25€

size M and color blue = 27€ / size M and color red= 29€

the prince doesnt change between them

Best regards