Normal shading bug with Render Instances

[John_Do]

I've just stumbled upon this weird "bug", I don't know how I didn't notice it sooner.

The 3d model of the wall is from Quixel, no displacement, just a normal map.

IR - Instance : correct result


IR - Render Instance : weird shading


Prod - Render Instance : weird shading, like a blend between both results.


Another example



Corona 12.2 hotfix
Cinema 4d 2025.2.1

[maru]

This bug is reported as (Report ID=CC4D-955) and unfortunately it is still there in V13.