Unexpected XML Declaration. XML Declaration must be the first node in the document and no whitespace characters are allowed to appear before it linit

Question

I'm having some trouble with xml declaration and encoding. I have some excel files which have an issue with the encoding/declaration. I have no control over how the files are created. They are received directly from a client

I'm trying to using C# to rewrite the declaration and insert a the first node. However I keep running into the same response. I understand the error message is clear, what's not clear to me is why the newly created declaration is not solving this issue.

I assumed because it reads as the first child in the node which I checked and by prepending it would solve my issue but it hasn't. I've been stuck on this for quite a while. Any push in the right direction would greatly appreciated.

Error occurs on the last line --> var worksheets = xlPack.Workbook.Worksheets;

Actual error message -->

Unexpected XML Declaration. XML Declaration must be the first node in the document and no whitespace characters are allowed to appear before it line 2 position 1228.

sample xml

<?xml version="1.0" encoding="utf-8" ?>
<p:properties xmlns:p=http://schemas.microsoft.com/office/2006/metadata/properties xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xmlns:pc=http://schemas.microsoft.com/office/infopath/2007/PartnerControls>
<documentManagement />
</p:properties>

using (StreamWriter sw = new StreamWriter(filePath + exportFileName))

                {

                    using (ExcelPackage xlPack = new ExcelPackage(new FileInfo(importFile)))

                    {

                        var xmlDec = xlPack.Workbook.WorkbookXml.CreateXmlDeclaration("1.0", null, null);

                        var root = xlPack.Workbook.WorkbookXml.DocumentElement;

                        var roottwo = xlPack.Workbook.WorkbookXml;

                        var originalXMLDec = roottwo.FirstChild;

                        var originalXMLDecread = roottwo.FirstChild.Value;

                        var firstChildCheck = roottwo.FirstChild.NodeType;

                        var checkNodeType = xmlDec.NodeType;

                        roottwo.RemoveChild(originalXMLDec);

                        roottwo.PrependChild(xmlDec);

                        var rootTwo = root.InnerXml;

                  var worksheets = xlPack.Workbook.Worksheets;