Weird Error - CPF3E01 - DDM parameter value not supported. (using Db2 Connect driver for .NET Core)

Scenario
Db2 Connect driver for .NET CORE

Calling an external stored procedure written in RPG.

As long as the results set is 1192 records or less, it works fine, but any
bigger and we get the following exception on record 1193.


CPF3E01 Diagnostic 40 01/22/20 18:09:47.424155 QCNTEDDM QSYS *STMT QRWTSRVR
QSYS *STMT

From user . . . . . . . . . : DT1PYDC
From module . . . . . . . . : QCNTEDDM
From procedure . . . . . . : SNDMSG

Statement . . . . . . . . . : 8629
To module . . . . . . . . . : QRWTSRVR
To procedure . . . . . . . : main
Statement . . . . . . . . . : 325
Message . . . . : DDM parameter value not supported.
Cause . . . . . : A value was sent from the client that is not supported by
this server. The following are not supported (See X'2156'): -- '1144'X or
'212D'X -- Version names. -- '2106'X -- Decimal precision of 15. -- '2112'X
-- Package names or collection identifiers greater than 10 characters in
length. -- '2128'X -- Collection identifiers greater than 10 characters in
length. -- '2129'X -- Release of allocated resources at conversation
deallocation. IBM i supports release of resources only after commit. --
'2130'X -- Option to explain information about SQL statements. -- '2131'X --
User IDs greater than 10 characters in length. Recovery . . . : Change
the value sent by the client and try the operation again. Technical
description . . . . . . . . : If DDM code point X'2156' does not appear in
the list above refer to the DDM Architecture Reference for more information.

Doesn't matter what's in the results set, only if it bigger than 1192.

Calling the same store proc via JBDC using ACS Run SQL Scripts works fine.

One thing that's a little different, the results set is built as an RPG
Array...

dcl-ds my_data qualified dim(9999);
ENTERPRISE char(4);
COMPANY char(3);
EMPLOYEE_ID char(9);
TECH_ID char(3);
//other fields snipped
end-ds;
dcl-s OutputRows int(10);

Exec SQL Set Result Sets
WITH RETURN TO CLIENT
ARRAY :my_data
FOR :outputrows ROWS;

Thoughts?
Charles