Glass splashbacks - glue visible through

Hi there, can anyone help please?

We've got glass splashbacks in our kitchen. They were made by a good company, toughened, painted behind with a foil backing, and secured with the right kind of glue. But after about 3 months, the adhesive behind the glass started to show through. They replaced the glass (they thought maybe there had been a fault with the paint) but it has recurred.

Now they have no idea what's wrong; they are talking about UV degradation and fitting UV-protection film to the windows but this sounds unlikely: it's a basement kitchen with a north-facing window. So not much UV.

Has anyone come across this problem?

Thanks a lot if you have any sugestions.