Hi Sourabh,
As I know, this bug occurs if you change SPL status via transaction code BP. For example, BP is in positive list, you directly mark it blocked. Nevertheless GTS reports which are relevant to blocked business partners work fine because the standard implementation combines field spl_chk_positive and splpn to determine the status of BP address like:
Release status: spl_chk_positive is initial and splpn is initial
Block status: spl_chk_positive is not inital and splpn is initial
Positive List: spl_chk_positive is initial and splpn is equivalent to 1
Negative List: spl_chk_positive is not initial and splpn is equivalent to 2
If you have own development to collect SPL status for business partners, you have to correctly handle this case.
Hope the above information help you to resolve your problem.
Regards, Boer