Maybe this one has been spotted in the wild -- but if I have a vrayblend material (base) with reflection, and then make it a matte object the reflection doesn’t show up. If I copy the base material into its own (non-blend) material, it’s fine.
Yep, currently the reflections on matte objects will show up only if a vraymtl material is applied to it directly.
Best regards,
Vlado