Shadows not rendering with GPU?

Hello, new blender user here.

I’m doing the donut tutorial from Andrew Price. In fact… I finished it, but now I saw that whenever I render with my GPU and OpenCL (AMD RX 5700 XT), there is no shadows casted on my render… But they are on the Viewport…

What’s more, when I render with my CPU (Ryzen 5 3600X), I get those whadows on my render…

And when I render with BOTH my CPU and GPU to gain time… I end up with some blocks with no shadows…
I regrouped all my renders here : https://postimg.cc/gallery/1tbx3z23u/

I tested that in Blender 2.81 (for the denoiser), and 2.80, it’s the same.

Has anyone encountered this?
Does a solution exist? Using my GPU would be usefull for speeding up renders.

Thanks!