I've been trying to render out a simple fire/smoke sim. Everything looks fine in viewport but when rendered the flames do not show. I'm using cycles with optix in blender 2.83 steam release, on windows 10.
I have tried changing shader setups just to see the same thing, that the flame and temperature volume info seems to look fine in viewport, but be abscent from render, changing number of light bounces, and volumes step rates and max steps.