Best Sellers Products Special Status , Special Price issue

[Asset]

Dears ,
When I try retrieve the value of "specialStatus" , "specialPriceExTax" or "specialPriceIncTax"  for any of Best Sellers products  of KkAppEng.getProductManager.getBestSellers () , They are alway 0 , null , null respectively .

despite they have values in any other Lists [ e.g New products ,  Product details ]  for the same products

I have tried the server APIs as well , but same behavior.

any idea why this occur !

Best Regards,