Possible color selection bug in Huion/Painter 2020?

Hi gang,

Thus far I've been pretty impressed with the speed of the brushes in Painter 2020 on my paltery Late 2009 iMac, running High Sierra, using a Huion Kamvas GT-191 V2 display tablet. But what's killing me is when I'm attempting to select colors via the color wheel within the Color pallet. Whenever I select a color within the triangle portion of the Temporal color wheel, then paint using my pen, my color instantly defaults to black. Stroking with the mouse works fine. Selecting color any other way works fine.

I was wonder if anyone else is having this issue. 

Thanks in advance!