Premiere Pro is using only 5–10% GPU during export. Is this normal?

I'm running Premiere Pro with an NVIDIA RTX 4070, CUDA is enabled, and GPU Acceleration (CUDA) is selected in Project Settings.

The problem is that during H.264 exports, GPU usage stays around 5–10% while CPU usage jumps to 90–100%. Export times are much longer than I expected for this hardware.

Things I've already checked:

• Latest NVIDIA Studio Driver installed
• Hardware Encoding enabled when available
• Media cache cleared
• GPU Acceleration (CUDA) confirmed
• Windows power mode set to High Performance

Has anyone experienced this? Is Premiere supposed to rely this heavily on the CPU for certain exports, or is there another setting I might be missing?