Hi Andreas,
there is a difference between the academic year and session of the assessment process, which is used for controlling the status of the graduation request (your first screenshot) and the academic year session stored in the graduation itself. You could for instance have a request in one period for graduation in another one. It is not even evident that the period (period group) used in the graduation must be the same as in the assessment process for that.
The request is stored in database table PIQDBCMPRRECORDS, the graduation itself is stored in additional data for relationship 532 between student and qualification.
Regards,
Dirk