Why isn't fire being loaded in the render view? I did some fire simulations in blender about a week ago. I encountered the same problem in all of them, the fire was not loading in the render view, all I get are some huge black pixels. It works well in the object view.
this is what it looks like in the render view.

I looked it up on Youtube and other forums, but I didn't find anyone facing this same problem.
I am using Blender 3.0(beta), but even when I opened the same project in older versions of blender it showed the same effects.
Your material setup is very awkward. Some things seem outright incorrect, like a color ramp being driven by color and then controlling emission strength. Start off with a default Principled BSDF, changing only the Color Attribute field from the default blank to the word color (uncapitalized).
For a custom flame color, perhaps use a plain emission shader, with the density attribute controlling the strength, and the temperature attribute going into a color ramp that starts with black. You may have to use a remap node so the temperature value so it ends up being 0 to 1.