Inconsistent output - Solution cost changes based on shipment id values

Hello,
I am getting inconsistent output from Jsprit. What I have observed is that for given problem, if shipment job ids remain consistent across runs then you get consistent output. However, if job ids across runs change then you get different value.

Any clue why value of job id should influence output.

Regards,
Amit

@stefan,@grantm009,@jie31best Can you please let me know your thoughts on this ?

Regards,
Amit