DB2 XMLSERIALIZE use in RPG program

[lcortesbsr]

So I'm trying to develop a function in AS400 RPG that receives 4 String parameters, uses DB2 XMLSERIALIZE to build an XML Header using said parameters and returns that header in a string. The return string shows different characters in the tag values when I use an RPG variable. I think maybe the problem is the character coding, but I've tried many solutions and none works.

Here's the code of the RPG function:

dcl-proc SWFS02801_generaHeaderMX export;[INDENT]dcl-pi *n Ind;[/INDENT][INDENT=2]bicFrom Char(12);[/INDENT][INDENT=2]bicTo Char(12);[/INDENT][INDENT=2]BizMsgIdr Char(20);[/INDENT][INDENT=2]MsgDefIdr Char(20);[/INDENT][INDENT=2]AppHeaderData Char(2000);[/INDENT][INDENT]end-pi;
dcl-s AppHeader SQLTYPE(CLOB:2000);
dcl-s bicFromClob SQLTYPE(CLOB:12);
dcl-c BizSvc 'swift.cbprplus.01';

bicFromClob_DATA = bicFrom;
Exec Sql SELECT XMLSERIALIZE([/INDENT][INDENT=2]XMLELEMENT(NAME "AppHdr", XMLNAMESPACES(DEFAULT
'urn:iso:std:iso:20022:tech:xsd:head.001.001.02'),
XMLFOREST(
XMLELEMENT(NAME "FiId", XMLELEMENT(NAME "FinInstId",
XMLFOREST( :bicFrom as "BicFi") ) ) as "Fr",
XMLELEMENT(NAME "FiId", XMLELEMENT(NAME "FinInstId",
XMLFOREST( :bicTo as "BicFi") )) as "To",
:BizMsgIdr as "BizMsgIdr",
:MsgDefIdr as "MsgDefIdr",
:BizSvc as "BizSvc",
CubDDat.UbdFGenFec(Current date) as "CredDt"[/INDENT][INDENT=2])[/INDENT][INDENT]) as CLOB(2000) ) AS RESULTADO
INTO :AppHeader
FROM SYSIBM.SYSDUMMY1;
If SQLCODE = 0;[/INDENT][INDENT=2]AppHeaderData = AppHeader_DATA;
return *on;[/INDENT][INDENT]Else;[/INDENT][INDENT=2]return *off;[/INDENT][INDENT]ENDIF;[/INDENT]
 
 END-PROC;

The problem is specifically in the variables: bicFrom, bicTo, BizMsgIdr, MsgDefIdr.

The expected XML Header is the following:

<AppHdr xmlns="urn:iso:std:iso:20022:tech:xsd:head.001.001 .02">[INDENT]<Fr>[/INDENT][INDENT=2]<FiId>[/INDENT][INDENT=3]<FinInstId>[/INDENT][INDENT=4]<BicFi>BICFROM1</BicFi>[/INDENT][INDENT=3]</FinInstId>[/INDENT][INDENT=2]</FiId>[/INDENT][INDENT]</Fr>
<To>[/INDENT][INDENT=2]<FiId>[/INDENT][INDENT=3]<FinInstId>[/INDENT][INDENT=4]<BicFi>BICTO1</BicFi>[/INDENT][INDENT=3]</FinInstId>[/INDENT][INDENT=2]</FiId>[/INDENT][INDENT]</To>
<BizMsgIdr>tstBizMsgIdr</BizMsgIdr>
<MsgDefIdr>tstMsgDefIdr</MsgDefIdr>
<BizSvc>swift.cbprplus.01</BizSvc>
<CredDt>2021-12-28T06:00:00.0Z</CredDt>[/INDENT]
 
 </AppHdr>

And the (incorrect) output that is returned is the following (notice the tags BicFi, BizMsgIdr, MsgDefIdr, BizSvc) :

<AppHdr xmlns="urn:iso:std:iso:20022:tech:xsd:head.001.001 .02">[INDENT]<Fr>[/INDENT][INDENT=2]<FiId>[/INDENT][INDENT=3]<FinInstId>[/INDENT][INDENT=4]<BicFi>wsnDxtnW1PFAQEBA</BicFi>[/INDENT][INDENT=3]</FinInstId>[/INDENT][INDENT=2]</FiId>[/INDENT][INDENT]</Fr>
<To>[/INDENT][INDENT=2]<FiId>[/INDENT][INDENT=3]<FinInstId>[/INDENT][INDENT=4]<BicFi>wsnDxuPW8UBAQEBA</BicFi>[/INDENT][INDENT=3]</FinInstId>[/INDENT][INDENT=2]</FiId>[/INDENT][INDENT]</To>
<BizMsgIdr>oqPCianUoofJhJlAQEBAQEBAQEA=</BizMsgIdr>
<MsgDefIdr>oqPUoofEhYbJhJlAQEBAQEBAQEA=</MsgDefIdr>
<BizSvc>oqaJhqNLg4KXmZeTpKJL8PE=</BizSvc>
<CredDt>2021-12-28T06:00:00.0Z</CredDt>[/INDENT]
 
 </AppHdr>

Any ideas are welcome. Thanks in advance!!!