Elevation consistently inaccurate (reading too low)

I'm having issues with the Instinct reading lower elevation than it should, which results in considerably lower elevation gains than what you should be seeing. One might be tempted to blame this on sweat, poor weather conditions and what not, but that's actually not the case. I'm noticing this on a very short ride (roughly 11km). Start and finish elevation are typically within 5m of each other (which is IMHO fairly accurate). I've had three different devices prior to this one (cycling computers)

After looking more closely at the graphs, I've noticed that the Instinct just plain out ignores certain elevation gains, and instead chooses to think I'm riding a flat profile. It does so very consistently and given that the starting and ending point read the same elevation, I'm inclined to believe this is a sofware issue. Naturally, the watch mode is set to altimeter. 

So my question is whether this is a known issue and whether I can expect a fix. Difference of 40m in 11km is pretty big in my opinion.