I was using odoo 14 and the serial scanning during the delivery  order process was very smooth. All I did was scanning the serials and odoo was picking up the serials one by one. 

Recently I have upgraded to odoo 17 and now I have found that there is no such functionality around the scanning. 

steps

1. all my items are serials

2. create a sales order with 1 item with 3 qty

3. click the delivery option (lorry button)

4. then in the wh/out/# screen , i select the bullet icon (icon with 4 lines) in the right hand corner. There I can only see  "add line" option where odoo expects user to select existing serials. However our requirement is to scan the barcode and pick it by odoo. 

5. Even I tried the serial # column in the wh/out/# screen, but when I scan it, it throws a warning message for every scanning. 

We so far are struggling with odoo 17 for serial selection during delivery order. It was very smooth in odoo 14. 

Awaiting for your valuable insights.