Okay, thanks for the tip. There really aren’t many to be honest. I have a Skylight, a Keylight, Fill Light, and Rim Light. There were some Point Lights, but I’ve removed those. And I’ve also re-baked everything in the scene.
Ahh, it’s actually Alt + 7. 
But it looks like the head is in the orange/red with all three lights on.
However, I’ve still noticed the flickering even if I turn the Key Light to 0/off.
I have enabled ray-tracing in the Project Settings, but I can’t imagine that’s the cause.