I notice the offset problem in your example, but it is hard to see - it has the size of about 1 pixel only. It disappears totally on higher shadow map resolutions like 1024x1024, so it looks very different than in your screenshot. It seems to be just an aliasing error.

I've also checked the code, but the cube maps are created correctly and the render offset is also correct - so I can't confirm any problem there.

You mentioned in the comment of your script that the problem disappears when you create the cube map with a DirectX function. But that had to be the same function that the engine uses. Can you also upload an example where the offset disappears, or send it to support at conitec.net? I'd like to compare both.