STO: why the delivery date is not updated in ATP check after route changing?

After the route is changed in STO, the delivery date is not updated in the ATP check,so the availability check refers to the old route, not to the new one.

Only after the PO is saved and opened again, the delivery date is updated and the ATP check can be calculated correctly, but the users can not work this way.

How could this problem be solved?

Thank you for your help!