Speed camera flash even though driving at lower speed

Hello,

We’re on our first road trip to Switzerland. Today on our way to Grimsel Pass, I saw a mobile speed camera flash near Innertkirchen, when my speed was 71 km/h where the speed limit was 80 km/h.

Please see the attached video from my Tesla dashcam:
https://we.tl/t-qgmW1QTQZgDZ2LbB