Massive performance degradation from 5.2.0.M1 to 5.2.0.M2

the drools-planner SolutionInitializer takes 75 minutes to complete im 5.2.0.M2
5.2.0.M1 took 9,5 Minutes

It also seems that accumulation queries with init, action, result sections break down completely in performance.
The following query takes now 3 minutes 45 secs to complete. Before it was ~1 sec.
The cardinalities:
PostingPeriodOpt = 5
MediumLocationOpt = 25000
MediumBookingOpt = 13000

query "queryMediumPartlyTaken"
$pp : PostingPeriodOpt()
$mlo : MediumLocationOpt(mTypeId == $pp.mTypeId)
$mp: MediumPeriodUsage( subOptimal > 0 ) from accumulate(
$mbo : MediumBookingOpt ( mediId == $mlo.mediId, eval(timeInterval.overlaps($pp.getCycle())) ),
init ( MediumPeriodUsage $mpu = new MediumPeriodUsage($mlo, $pp); ),
action( $mpu.addBooking( $mbo.getIndexRange() ); ),
result( $mpu )
)
end