Problem on Ray Tracing Transparent Reflection

Hello,

I recently tried the ray tracing feature using unity 2021.2.5f1 and has the following problem :-

I set up the DXR raytracing environment and build a simple screen using the come-with indoor template.
The scene has two light source one cube object and one reflective plane (vertical)
The mirro image of the cube reflected on the plane has the following problem :-

If the cube material is opaque , the mirror image is fine
If the cube material is transparent, the mirror image dosen’t show the reflected cube
If I switch on path tracing, the mirror image is fine with transparent material

Did I miss out anything to make it work on Ray Trace , or the current 2021.25f1 build dose not support
real time ray trace reflection of transparent material ?

Any advise is appreciated.
Thanks in advance.

Unity Project of the problem scene can be download from this link

https://drive.google.com/file/d/1R9-6lBj-aEd9dpZZHfxeM4rd-bnkIGIS/view?usp=sharing