Garmin Venu is a joke! No heartrate, if wearing a shirt at home. Long sleeves solve the problem! Best to stay in bed, where it's nice an warm :(

Mine is doing just fine with wearing gloves en multiple layers of clothing...

Yes, no problem on the bike wearing gloves.

But just a simple walk outside without (at around 5 degrees) and heart rate goes away.
When ski touring (uphill) I never wear gloves, as it's just too warm. Also it's nice to get rid of excess heat without gloves.

What I find interesting is, that the old Vivoactive HR never lost heart rate in the cold.

I never have a problem with that. I just did a run at 2 degree celsius and I have valid heart rates. 

I'm going to return that POS!

1st time it lost heart rate during breakfast, reboot and it only came back during my bike ride - ridiculous!

I've worn gloves and the unit even was under a layer of clothing.