It looks like we're getting a different data structure sent back from the Amber signer since version 2.0.6 - nostr:npub1w4uswmv6lu9yel005l3qgheysmr7tk9uvwluddznju3nuxalevvs2d0jr5 has anything changed on your side since this version? It looks like when we call sign_event we are getting the npub returned in the 'event' field rather than the signed event json.