Sending a receipt does not send timestamp correctly

When I receive a message in a workflow and want to send a receipt, it fails with the error message:

2025-11-08T14:41:26.691Z [pool-7-thread-2] DEBUG o.asamk.signal.jsonrpc.JsonRpcReader - Received json rpc request, method: sendReceipt
2025-11-08T14:41:26.695Z [pool-7-thread-2] WARN  LibSignal - [SignalServiceMessageSender]: [1762612886695] Hit unknown exception: b598d90b-fec0-4da4-a0aa-581e124d47a4
java.lang.NullPointerException: Parameter specified as non-null is null: method org.whispersystems.signalservice.internal.push.ReceiptMessage.<init>, parameter timestamp

The timestamp parameter is correctly set in the "send a receipt" node. Neither a static timestamp nor a timestamp taken from the received message (dataMessage->timestamp) works, it results in the same error.

I looked through the source code of signal-cli and this project and the messages look consistent at first glance.

Any idea on how to get the actual message sent to the signal-cli service logged? Looks like even with --verbose, signal-cli is not logging the incoming JSON message.