I feel like I received a used product.
Did your thermometer also come with Duracell batteries already installed? I'm expecting these to come separately, not installed...
I mean that the batteries were not inserted, but were included in the package. But was the packaging no longer sealed? There should have been an adhesive seal on the openings. But I can't remember exactly what happened to the batteries, but even if they were, it's quite possible that it was changed at some point. To be 100% sure, why don't you contact Braun customer service?