Why is the same UPC code showing for all my products?

[Lusatian]

1- I added UPC codes to all my products. after I'm done, i found out that only one UPC code showing/ applied to all the products. Why is that?

2. is the user able to copy a whole column of different UPC  barcodes into the bulk editor section?

I was hoping that I can do that, but to me seems like it's manual per item.

Thanks