Premiere Pro is using GPU and CPU for rendering.

When I render a premiere video it is using the gpu and the cpu in intervals. At the moment of starting the render, the pc uses the gpu and then uses the cpu, then almost at the end of the render it uses the gpu and at the end it uses the cpu again. I am almost sure that this was not happening to me since the render times are now longer than before. Any help?
I have Premiere Pro 2025 last version, an i912900k and a GEFORCE RTX 3090