Arona sensor issues

I had a similar sensor fault issue with my Arona. The rain detection was completely off. I'd suggest checking the sensor itself. Is it possible there's something obstructing it, or perhaps the gel pad is damaged?

Interesting! Where exactly is this gel pad located? And how would I even check for damage or bubbles? I'm not the most mechanically inclined, but I'm willing to give it a shot before taking it to a professional.

The gel pad is between the sensor and the windshield. It's used for rain detection. In my case the sensor malfunctioned due to bubbles forming under the gel. You can visually inspect it, but the sensor is located on the windshield so it could be challenging to see it properly. I recommend visiting a workshop.

Took it to the workshop. You were spot on! Bubbles under the rain-light sensor gel pad. New sensor fitted, cost me 62€. Thanks a million for the help!