Hi,
I'm sorry to hear you're facing these troubles. Unfortunately, V-Ray Standalone isn't "fully" supported, and therefore neither is the Chaos Cloud - as mentioned in their documentation:
"You can verify that your job will be processed correctly by rendering locally with V-Ray Standalone. If these results look correct, then you should get the same results in Chaos Cloud." In the case of “billboards”, instead of using the
Template option, please use the
Custom Object and assign a material without the
Forest Material (like in mentioned for example
in this post).
I hope that helps.
Best regards,