Side Assist and Exit Warning system

[Bardreg]

A couple of months ago during moderate rain a warning came up that the Side Assist was not active. I looked at the sensors and they were only wet not mud covered. Then yesterday it rained again - nothing torrential , just normal English rain - and Side Assist stopped working and also the Exit Warning system. Today, in the dry, things are OK again. Last time the dealer wondered if the problem was due to the sensitivity of the sensor ( but I never had a problem with the sensors on my old T Cross.) Has anyone had similar problems? if so, what was the cure? Wonder if mud flaps would help or is water getting into the electrics?