Dear Petr,
Did you cross check Closing stk of One Material and One plant(plant which is having issue) at Bex end with MC.9/MB5B.
Then cross check all the movements coming from opening stk of the day when have done BX initialisation and further movements.
Then you will come to know the issue at single material level.
Then will check issue at final conclusion level.
Although user is posting issues with future data, it wont impact marker.
Waiting for your feedback,
Best wishes, Vijay.