Black squares showing in final render

Hey guys, I’m following a tutorial right now and I have a problem with my final renders.
I’m using open cl with my AMD RX 5700 XT and AMD RYZEN 7 3700X since it faster,

image

but the problem that I found out that is whenever I would use both of them black squares show up like this.

but when I try to use just my cpu or just my gpu to render the black squares don’t show up.

Anybody know the reason behind this?

If you’ve used the experimental setting for cycles, some things may not work with the GPU.
If you are using eevee, take a look at the blend mode settings of the material that best fits.
experim