Not sure how to best describe the issue, but the boot glass has water or sealant discoloration underneath the black border, under the glass itself.

I would just think about a replacement or changing the boot but I've got a rear tint (Not done by me).

Any ideas what has caused this or if it's possible to revert it.

Image will be attached shortly, phone refuses to upload.

Its a common problem and as far as i know the only way to solve is to get new rear screen glass fitted.

Whoops sorry,I did do a search, just very difficult to come up with a suitable keyword.