Cannot Re-Add eB Procedures to Event Handler

I removed the out of the box procedure EBH_ON_ECP_REWORKED from the OnWorkTaskReworking event handler for a test. When I went to add the procedure back onto the handler, it did not appear in the list of procedures that could be added. It appears the parameter types are not matching up. The handler expects the ps_sender input to be an NVARCHAR2 value. However when running the EBH_ON_ECP_REWORKED procedure on its own in SQL Developer, I see that ps_sender is a VARCHAR2 value. Because these parameter types are not matching up, I cannot add EBH_ON_ECP_REWORKED back onto the OnWorkTaskReworking event handler. The same problem exists for the ETMH_ON_REWORKING_TASK procedure, which is also on the event handler.

Why are the parameter types different in the procedures than what is required in order to use them in the event handler? This is preventing us from completing UA testing.