ARFoundation weird artifacts using shader from shader graph library with Post Processing

Hello,

I am experiencing a very weird issue in ARFoundation 4.0.0p3.

See video here.

I am using unity 2019.3.13f and I opened the ARFoundation samples master repo. I then installed URP, followed the instrauctions to setup the Forward Renderer and opened shader graph.

I copied this shader from the shader graph sample library repo and applied it to an avatar in my scene. I haven't changed the shader at all.

I then created an empty gameObject and added a Volume component to add the bloom fx. If the fx is active the issue appears, even if the colour properties in the shader are not HDR.

Also, as soon as I disconnect the Normal Unpack node from the normal input on the PBR master, the problem goes away.

The issue manifests itself on older Android devices, like a Pixel 1 for instance, on on iOS (tried iPhone XS and 7) but NOT on my Pixel 4 or my Pixel 3a..

Can anybody tell me what's going on here???

Many thanks

Michele