I have built a globe with satellites orbiting it.  All on one startdust layer.  A few days ago I added an obstruction layer and it worked fine.  Hiding the orbiting particles when they went behind the globe.  All of a sudden the obscuration layer now obscures part of the globe on the top right.  It’s also smaller.

I haven’t changed the position (which matches the position of the emitter).  The layer is 3D, I’ve got it set to Effects & Mask.

I’ve got a previous version where the obscuration works, but there been quite a lot of work done since then. 

any ideas?