Using policy collections with samples to review movers

If you create a sample category and set it to be cleared on the next access review I noticed it does not clear the sample if you want to run multiple attestation policies with the policy collection. I thought the idea of the collection was to run multiple attestation policies using the same sample and same schedule but it seems that using it this way does not clear the sample set. If I assign the sample to a single attestation policy and run that then the sample gets cleared as expected.

Is this a defect or am I missing something with this concept? Or is it just something with my test case? Using v. 9.1.