The rain rain sensor on the solar powered fresh air skylight seen here is the small gray box on the right side of the panel attached to the bottom of the skylight.
Velux skylight rain sensor problems.
This could be due to the sensor being shielded by the window sash on a steeper pitch.
The skylight is then flashed sealed to become part of the roof.
A wire extension can be ordered directly from velux to accommodate moving the sensor panel.
In this case the rain sensor may need to be relocated.
A velux skylight installed with a velux flashing kit is guaranteed leak free for 10 years.
If there is an issue with the effectiveness of the rain sensors it will be subject to a service request from velux.
A deck mount skylight unlike a curb mount skylight is simply attached directly to the roof deck.
Based on the above we should expect to get paid for the installation that delivers what it promises.