Asset ID (AUTO-ASSIGN) setup on Receipt but not being populated on voucher

We have created a PO and the created Receipt of that PO. We have setup Asset ID to AUTO ASSIGN and set the tag# and serial ID on receipt. Run the interface receipt process and the status has been changed to Moved.

Then we create voucher and copy the lines from Receipt. Here Tag# and Serial ID has been populated (as set on the receipt) but asset ID has not been populated and it is showing NEXT.