So you were expecting a diagnostic reply from a description of faint
vertical lines?
Ya, right.

You need to have a tech who is trained on that specific Samsung model
and has seen several of them so they can determine if this is really a
fault with the unit or just normal for the design.

Maybe not the answer you wanted, but the only and obvious answer.

Otherwise, take the defective thing back as it obviously does not have
the quality you expected and get a refund so you can buy another one.