MacBook Pro 16" runs about 10 degrees hotter when plugged in on idle, is this normal?
The new Macbook Pro 16" has problems with external displays connected to it, sometimes even just external hdd's or other thunderbolt devices.

Do you have external displays connected? 

Basically the GPU will get pinned at 18watt+ and produce max heat on the right side of the laptop where it is located.
This will cause the laptop to go at 60 degrees C at idle and 3k~ rpm fans, and spike to 100+ degrees under CPU load.

Apple has not responded officially to this, even though I am in multiple forums that have people mentioning they contact Apple support that have them go trough random tests that does nothing.
Please call Apple and report this issue so we get as many people reporting it as possible.
I have scheduled calls with them, that they keep postponing.

If you want to see for yourself istat menus can show you the information, it should have a trial so you can see it.

Short video of me having laptop unplugged and plugged with istat menus open:
https://www.youtube.com/watch?v=u3vV1-CWMQg

I have installed Turbo Boost Switcher, and turned off Turbo Boost for the time being or my Macbook will go into thermal shutdown on intense cpu tasks. 
Yay for getting an i9 cpu locked to 2.4Ghz the performance is terrible. 
Hoping Apple will eventually let me return it for money back, I'm over my no questions asked return days.