Blueprint hierarchical instanced static mesh not visible in ray tracing refraction?

Trying to use blueprint hierarchical instanced static mesh in my scene, I notice that it’s not showing in refraction if refraction in Post Process Volume is set to use ray tracing.
I placed my static mesh in level manually, and they all show up in refraction. My blueprint looks fine in viewport just not visible in refraction.
Does anyone know if it’s a limitation or I did something wrong?