960 indicator lights not self cancelling?

My new 960's switch doesn't self cancel after a turn (it's a UK RHD
'95 estate with the later low bonnet)

Before I dismantle it (airbag and all), does anyone have experience of
this fault? Am I likely to find it's the switch itself or something
else? Is it repairable, or do I have to swap for a new switch?

Ideally I'd only like to have to strip this complicated assembly down
just once. If I will definitely need a new switch, I can get one
beforehand.