Hide particles in Raytraced reflections

Any advanced Raytracing experts here?
Making use of Raytraced reflections in a cinematic. The problem is I also have a particle ‘dust’ system which isn’t reflected properly. Instead of translucent sprites all I see are opaque square tiles (circled in blue) If I switch to Lumen or screen space reflections they disappear completely.
Easiest solution I assume is to hide the particles from Raytracing reflections. But how?
HideParticles