KP97 values are incorrect with Cost center group

Dear Gurus,

I have a problem with KP97, where till last month copying was perfectly done but this month it is not copying all the cost centers data when I doing it by giving the cost center group. If I copy with individual cost center it is coming perfectly. What is the problem with Cost center group while using KP97.

We have plan values in source period.

Thanks in advance

Regards