My T865 is not really IP67 waterproof

Hello, I received my T865 a little over a week ago and am basically very happy with the tablet;-) However, I am disappointed with the claimed IP67 waterproofness of the device. I drove back to Switzerland from Corsica via Italy 2 days ago and had about 2 hours of medium rain on a 1250GS (behind a high windshield). The device still works perfectly, but the next day I saw that drops of water had formed on the back under the cover for the light (see picture). I would like to emphasize that of course all covers were tightly closed. Unfortunately, the drops have not yet disappeared and even if they had, this does not leave a good feeling for the next trip. Any ideas?