You mean that crack in the center of the optical sensor? It's a very common issue across many garmin models. Garmin's support policy seems to be to treat it like a cosmetic defect with no impact on performance or functionality, hence not covered by warranty.
If you have the receipt and you are in Europe, you have warranty for 2 years and they replace it with a new one.Mine was replaced 3 times for the same reason. The last one has no cracks for more than 8 months now. Hopefully it will stay as it is now.
