ID.4 USA defective defrost grid (Any one else?)

The lines of the defrost grid on the rear window in my brand new ID4 pro S have some irregularities/discoloration to it. It is only noticeable when viewed from the inside of the window. It appears to possibly have malfunctioned and overheated/burned. I have never used it and discovered this issue only hours after taking delivery of the car last Friday. Immediately I called VW and they insisted that I take the car in to the dealer for an inspection.

So I took the car in for inspection at my local VW dealer first thing Monday. The service manager suggested that we compare the grid to another pro S on the lot. The other pro S also appeared to have the beginnings of the same issue. They service manager tried to tell me that this is just normal and part of the curing process. I don't believe that this is correct or acceptable on a brand new car. It makes me quite concerned about the quality and safety of this car. I have insisted that they escalate the case to the RCM supervisor but so far they are unwilling to do anything about the issue. They seem more interested in stalling and deflecting than actually addressing the issue and making things right. I love the car but am so disappointed in VW customer service.

Does anyone else have this issue and any advice how to get traction on a replacement with VW?