APO Product Planning Table - displays only 13 periods despite of 2 years horizon

Hi,

I face an issue I have never seen. In APO, I enter the product planning table with a time horizon from now till August 2017, so more than 24 months.

But in the "product view: periodic" the system displays only 13 periods, despite of the time horizon entered and despite the period type, day, week or month. And I don't know why?? see below.

now on weekly level

any idea where the root cause might be?

thanks in advance,

Pilvi