As you're using the V-Ray 3.2, please take in mind, that as mentioned here
: "... V-Ray and V-Ray RT supported versions are 2.5 or greater for V-Ray 2, and 3.3 or greater for V-Ray 3
. Upgrading the V-Ray to a newer version would be highly recommendable. As far as I know, if you're already using any of the V-Ray 3.x version upgradings to another 3.x version should be free of charge and there are significant speed improvements."