In 5.1 this issue is still present:
I tried every combination of shading models for both the glazing and the railing but no luck.
If there is a way to disable reflections when raytracing for certain objects, in this case the glass railing, that would help a lot. Unfortunately disabling “Visible in Reflection Captures” does nothing when using raytracing.
Ideally, enabling raytracing to bounce between transparent object would be the better solution. Doesn’t really matter if it’s expensive for rendered projects.