It's not an issue.

You're not seeing any GPU usage because you're not using any GPU. Rendering static pages doesn't require any significant resources. Once it does render it, since it's technically not doing anything, there's no more reason for the GPU to be utilized.

Using a GPU Benchmark tool, Unigene's Heaven, I ran a process that specifically calls the GPU. This is continually rendering a high resolution animation. As you can see from Activity monitor, the GPU is being utilized.

It's not an issue.

You're not seeing any GPU usage because you're not using any GPU. Rendering static pages doesn't require any significant resources. Once it does render it, since it's technically not doing anything, there's no more reason for the GPU to be utilized.

Using a GPU Benchmark tool, Unigene's Heaven, I ran a process that specifically calls the GPU. This is continually rendering a high resolution animation. As you can see from Activity monitor, the GPU is being utilized.

You can also do this with a simple video; localally via QuickTime, VLC, or Elmedia and even through a web browser like a YouTube video. Below is Activity Monitor with a YouTube video playing in a Firefox tab and again we can see GPU utilization