The images tell the story. At first, I though I was seeing lines because the video source quality was bad, but then when the issue was seen on all formats, I did some checks and this is the result. I have only had this TV for 3 days, I have applied for a replacement. I have a suspicion Amazon tries to give customers items returned by other customers - the reason I say this is because the TV came with fingerprint marks on the screen right out of the box.
I will update on the quality of the replaced item. If it is also not up to the mark, I am getting a refund. Panasonic is not up to the mark for a product costing 70K.
UPDATE JAN 2019
I received a replacement, thankfully the process was smooth. Clearly Amazon is first sending customers old returned products. The replacement I received still had the plastic stickers and wrapping on it, the first product did not.
As far as the backlight issue, there is still slight discoloration, but not as bad as the earlier one. The Panasonic technician said this will be seen on all panels and all brands. Apart from that, 4K quality is terrific, and the blacks on this panel are excellent. Sound is good too, though with some movies voice is overpowered by the bass.