SSAOPass and transparent background

I’m using SSAOPass and a renderer set with alpha: true.
On the ground of the scene there is a transparent plane (which is over a transparent background) that is generating occlusion (visible in SSAO ouput) but when the ssao image is blended over the main render pass image, the occlusion on the transparent plane vanishes and it is only visible over solid objects.

I tried (by trial and error) changing the blend settings of copy material in SSAOPass but without success.
Can anyone help displaying occlusion over transparency?

Do you mind sharing a live example so it’s possible to investigate the issue?

You can change plane transparency using the gui

It seems the occlusion attenuates the more transparent the plane is. Isn’t that the expected behavior?

What is your expected behavior? That the occlusion is not affected by transparency at all?

Yes, I would like to see the occlusion between the cube and the plane even when the plane is transparent

I don’t think this is physically plausible so I’m not going to invest more time in investigating this issue.

However, I understand the effect is wanted for artistic reasons.