How to resolve: XML schema created in Excel contains denormalized data - excel

Question

Edit/Update: By removing the <GrpHdr> element completely, Excel was able to verify the XML Map as exportable. My original question still remains, how can I solve the "Denormalized Data" error, with the <GrpHdr> included.
I am new to XML, and have been trying to import a source file (XML below) into Excel, create a schema/XML Map (unsure of the difference there) which I can then drag and drop onto two different tables:
One table contains one row of data for the Group Header: <GrpHdr> (Occurs ONCE)
One table contains multiple rows of data for the various Payments: <PmtInf> (Occurs MULTIPLE times)
I am able to successfully load the below XML into Excel using the Source button, and also to create an XML map off of it (which then appears in a "XML Source" window, showing the parent and child elements).
The problem I am having is in Verifying the XML Map for export. Excel says that the map contains "Denormalized Data". I have looked at various Microsoft resources, as well as on Stack Overflow.
Such as:
https://support.microsoft.com/en-us/office/issue-verifying-an-xml-map-for-export-fbfcdb77-c2d6-4040-b256-e584a71151b0
excel: Cannot save or export xml data. The xml map in this workbook are not exportable
Export denormalized data from excel to xml
Based on my research, I tried the following:
I have tried setting the MinOccurs and MaxOccurs attributes to be "0" and "unbounded" respectively, as I believe the default is "1" for both, and Excel's error saying that the XML Map contains "Denormalized Data" is due to having an element with the MaxOccurs set to "1".
I have also tried adding multiple <PmtInf> elements, so Excel knows (when creating a schema from the below sample file), that <PmtInf> is to occur multiple times.
Thanks!
<?xml version="1.0" encoding="utf-8"?>
<Document xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:iso:std:iso:20022:tech:xsd:pain.001.001.03">
<CstmrCdtTrfInitn>
<GrpHdr>
<MsgId>UNIQUE MESSAGE ID 35 AN</MsgId>
<CreDtTm>2016-05-26T10:07:00</CreDtTm>
<NbOfTxs>1</NbOfTxs>
<CtrlSum>0.01</CtrlSum>
<InitgPty>
<Id>
<OrgId>
<Othr>
<Id>ABC12345678</Id>
</Othr>
</OrgId>
</Id>
</InitgPty>
</GrpHdr>
<PmtInf>
<PmtInfId>ORIGINATOR REFERENCE 35AN</PmtInfId>
<PmtMtd>TRF</PmtMtd>
<PmtTpInf>
<SvcLvl>
<Cd>SEPA</Cd>
</SvcLvl>
</PmtTpInf>
<ReqdExctnDt>2016-05-26</ReqdExctnDt>
<Dbtr>
<Nm>DEBTOR NAME 70AN</Nm>
<PstlAdr>
<StrtNm>Street Name</StrtNm>
<BldgNb>Building Number</BldgNb>
<PstCd>Post Code</PstCd>
<TwnNm>Town Name</TwnNm>
<CtrySubDvsn>County/State/Region</CtrySubDvsn>
<Ctry>LU</Ctry>
</PstlAdr>
</Dbtr>
<DbtrAcct>
<Id>
<IBAN>NL39HSBC0123456789</IBAN>
</Id>
</DbtrAcct>
<DbtrAgt>
<FinInstnId>
<BIC>HSBCNL2A</BIC>
<PstlAdr>
<Ctry>IE</Ctry>
</PstlAdr>
</FinInstnId>
</DbtrAgt>
<ChrgBr>SLEV</ChrgBr>
<CdtTrfTxInf>
<PmtId>
<InstrId>PAYMENT ID 35AN</InstrId>
<EndToEndId>UNIQUE BENEFICIARY REFERENCE 35AN</EndToEndId>
</PmtId>
<Amt>
<InstdAmt Ccy="EUR">0.01</InstdAmt>
</Amt>
<CdtrAgt>
<FinInstnId>
<BIC>MIDLGB22</BIC>
<PstlAdr>
<Ctry>GB</Ctry>
</PstlAdr>
</FinInstnId>
</CdtrAgt>
<Cdtr>
<Nm>CREDITOR NAME 70AN</Nm>
<PstlAdr>
<StrtNm>Street Name</StrtNm>
<BldgNb>Building Number</BldgNb>
<PstCd>Post Code</PstCd>
<TwnNm>Town Name</TwnNm>
<CtrySubDvsn>County/State/Region</CtrySubDvsn>
<Ctry>GB</Ctry>
</PstlAdr>
</Cdtr>
<CdtrAcct>
<Id>
<IBAN>GB94MIDL40123487654321</IBAN>
</Id>
</CdtrAcct>
<RmtInf>
<Ustrd>Remittance Info up to 140AN</Ustrd>
</RmtInf>
</CdtTrfTxInf>
</PmtInf>
</CstmrCdtTrfInitn>
</Document>