I have an iPad Pro 11", which I noticed has a distinct smooth bend and lefts slightly in the middle on a flat surface

I have an iPad Pro 11" which I purchased just under 6 months ago. Despite great care, never dropping it, never sitting on it and using it in its folio case daily, I noticed the left edge (as you look at it in a portrait orientation) has a distinct smooth bend - so screen down, it lefts slightly in the middle on a flat surface. Screen and enclosure pristine. I wanted to sell it to fund a new MacBook Pro, but every buyer walks away as soon as they see this defect.

Took it to Genius Bar, was told they suspected accidental damage, so would replace for £160. After speaking to Apple Support technical gurus, took it to my nearest Apple store for a second opinion, same result but now quoting £380. I contend the product is defective and that according to their local terms of sale, they are responsible for defects and an obligation to repair or refund.

The Genius at the latest store says he sees these products every day and has never seen a bent iPad that wasnt accidental damage. Unfortunately, I'm now in a dispute - and profoundly sad to be here after many years of being a happy customer of theirs.

Anyone else noticing this defect on 2019 iPad Pro 11" models?

[Re-Titled by Moderator]