Visualize face normals messed up

Hi everyone, I'm having problems in visualize with assembly components displaying in this semi-transparent-almost woven look.  For example in the below image the faceplate is not supposed to be transparent.

I checked the usual culprits
the part has a plastic material with opacity set to zero

changing the material does not fix the issue.

I've checked for duplicate bodies in close proximity.

What's interesting is that if I insert the part by itself into the visualize scene it looks perfectly normal

It only does this when I attach an assembly and as you can see in the above image, not all assembly components do this.
I've tried forcing a rebuild on the assembly, saving it and re-importing it.
I'm not sure what I can do here.  Any help would be hot.

Thanks

John

(solidworks 2020 SP5.0/ Solidworks Visualize 2020/2021)

SOLIDWORKS Rx Diagnostics Report

System Manufacturer:LENOVO
System Model:ThinkPad P50
Card Manufacturer:NVIDIA Corporation
Card Model:Quadro M2000M/PCIe/SSE2
Your Current Driver:NVIDIA Release R450
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