Mavic bike computer

I just bought 2 mavic bike computers with cadence for myself and wife. During the Solvang Century my candence stopped working after 60 miles and my wifes speed stopped working after 90. Is this bike computer a piece of crap or is something strange going on?

Greyhound,

while i can’t speak of the brand new Mavic computer - as a shop we took a pass on picking it up.

i do know that all the previous incarnations are not very reliable.