2209 speed and cadence work flawlessly commuting to work in morning. However, riding home at 6pm the speed & cadence only works 25% of the time. Could it be the NiteRider Lumina 650 headlight mounted next to the 2209 main unit near stem? I do use different light settings during the ride and possibly the 25% is when the light is on the low setting (hard to correlate because it is dark). The headlight is off in the morning. If it is the light, any shielding possible? Not sure I can separate the 2209 and light by distance.

Thought it might be because the speed and cadence sensors sat outside in the cold all day (main unit taken off the bike during day) but now suspecting the light after reading a post or two. No low battery warning but replaced the speed sensor battery with no different results.