Shadow only visible when camera looks through transparent object

Good afternoon (o;

I am experimenting in 2.8 with some hologram/transparent effects involving the mix shader to fade between transparent shader and hologram shader…

When I navigate through the scene I can see a shadow when I look through the object:

The shadow is different when I move the underlying plane up/down…

But if I completely set the mix shader to only output the transparent shader, I still see the shadow:

Looking from the side the shadow is nowhere visible at all:

Something wrong with my node setup?

thanks in advance
richard

Ah solved it…had set AO bounces to 1:

Problem solved :wink: