Cash discount in F-28

Hi experts,

Please let me know why cash discount G/L account is getting reflected two times during F-28 incoming payment

Invoice values =171,739

customer payment = 170,022

cash discount = 1717 which should have been updated in single line,  but it is splitting into two line items...

001 40       0000500250 Cub-Ca-106553             170,022.00 (Bank account)

002 40       0000770070 Cash discount                   0.01

003 40       0000770070 Cash discount               1,716.99

004 15       0000100006 yeen traders           171,739.00- (customer

Based on the OBXI assignment this G/L is getting updated, in customer master immediate payment with 1% cash discount payment term  is assigned

Regards

Upendar