After having installed numerous kernels from https://kernel.ubuntu.com/~kernel-ppa/mainline/ I have now concluded that the regression on the Linux side happened between kernel versions 4.19.6 and 4.19.7. With that said, I will stop writing here and move to a Linux-centric forum / bug-reporter. I will add link here to that discussion once it has started for completeness.
Cheers!
Cheers!