When assigning a Blob or Clob from a ResultSet to a PreparedStatement parameter on a second connection, null is written to the column instead.
Attached the same example using Embedded->Embedded, Embedded->Network, Network->Embedded and Network->Network.
Only the Network->Network example exhibits the fault.
Originally discovered in HA-JDBC's sync code with 2 derby instances on Windows. Example were tested using MacOS. Both were running on Oracle Java 8 VMs.