I have a very simple setup in my compositor: Simply an image and a mask:
I want to mask out parts of the image that it is fully transparent except for parts of the image. The final image should look like this (simplified setup, later I want to use the image as overlay):
Apparently, the mask is applied, but somehow a semi transparent image is also applied.
I disabled background in camera (I actually deleted the camera and tried it). I disabled "Use for rendering" in view layer. I disabled the sequencer in output properties.
I actually thought this is not working, but it only seems to fail when looking at the render output in blender, the actual file is correct. Is this a bug or do I miss the option for this somewhere?