The search parameter VerificationResult attestation-who should not set multipleAnd to true. The element being searched VerificationResult.attestation.who has a cardinality of 1..1 and the parent element VerificationResult.attestation is also 1..1.  So searching with multipleAnd would always result in 0 results. 

Proposed Resolution:

1. Remove multipleAnd support from the searchparameter.