Mesh-renderer sort order not working on some devices

I have only managed to reproduce this on one computer a 2013 mac running macOS 10.13

It looks like the sort order of the mesh renderer doesn't work and that it renders them at the same layer/order in layer.

The mesh renderer uses a custom shader Render queue Transparent 3000.
The rest just use Sprites-Default

Very thankful for any hint on the matter

Unrelated but maybe worth mentioning, if the same mesh renderer is used on tvOS - and it is not covering the whole screen, the parts that appear behind it turn black.


EDIT:
I've managed to reproduce it on another friends 2013 iMac. Looks like it is a hardware issue with the shader?