PDFDocument write(to:) creates inconvenient pdf for Acrobat Reader

When I just open the pdf file, save it and open it with Acrobat Reader, then Acrobat Reader automatically change it. On close action the "Do you want to save the changes you made in the document  ..." dialog box is appeared.

This is my sample code:

Code Block swift
let pdfDocument = PDFDocument(url: URL(fileURLWithPath: "sample.pdf"))
if let document = pdfDocument {
	let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
	document.write(toFile: "\(documentsPath)/sample_copy.pdf")
}

The original sample.pdf document is opened and closed by Acrobat Reader without changes.
This problem doesn't occurred with Preview application.

Acrobat Reader after opening the sample_copy.pdf added this lines automatically to the end of the document:

Code Block 
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<?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>
<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.6-c017 91.164464, 2020/06/15-10:20:05    ">
  <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
   <rdf:Description rdf:about=""
      xmlns:xmp="http://ns.adobe.com/xap/1.0/"
      xmlns:pdf="http://ns.adobe.com/pdf/1.3/"
      xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/"
      xmlns:dc="http://purl.org/dc/elements/1.1/">
     <xmp:CreateDate>2020-10-27T10:42:03Z</xmp:CreateDate>
     <xmp:CreatorTool>Quadient Group AG~Inspire~14.0.28.13</xmp:CreatorTool>
     <xmp:ModifyDate>2020-10-27T11:42:13+01:00</xmp:ModifyDate>
     <xmp:MetadataDate>2020-10-27T11:42:13+01:00</xmp:MetadataDate>
     <pdf:Producer>iOS Version 14.1 (Build 18A8394) Quartz PDFContext</pdf:Producer>
     <xmpMM:DocumentID>uuid:64db6ce1-b87c-004d-a9bc-7a66b29b9f29</xmpMM:DocumentID>
     <xmpMM:InstanceID>uuid:fa313a45-ffb7-ed4e-b9f8-9916fa4000a5</xmpMM:InstanceID>
     <dc:format>application/pdf</dc:format>
   </rdf:Description>
  </rdf:RDF>
</x:xmpmeta>
<?xpacket end="w"?>^Mendstream^Mendobj^M122 0 obj^M<</BaseFont/Helvetica/Encoding 124 0 R/Name/Helv/Subtype/Type1/Type/Font>>^Mendobj^M123 0 obj^M<</BaseFont/ZapfDingbats/Name/ZaDb/Subtype/Type1/Type/Font>>^Mendobj^M124 0 obj^M<</Differences[24/breve/caron/circumflex/dotaccent/hungarumlaut/ogonek/ring/tilde 39/quotesingle 96/grave 128/bullet/dagger/daggerdbl/ellipsis/emdash/endash/florin/fraction/guilsinglleft/guilsinglright/minus/perthousand/quotedblbase/quotedblleft/quotedblright/quoteleft/quoteright/quotesinglbase/trademark/fi/fl/Lslash/OE/Scaron/Ydieresis/Zcaron/dotlessi/lslash/oe/scaron/zcaron 160/Euro 164/currency 166/brokenbar 168/dieresis/copyright/ordfeminine 172/logicalnot/.notdef/registered/macron/degree/plusminus/twosuperior/threesuperior/acute/mu 183/periodcentered/cedilla/onesuperior/ordmasculine 188/onequarter/onehalf/threequarters 192/Agrave/Aacute/Acircumflex/Atilde/Adieresis/Aring/AE/Ccedilla/Egrave/Eacute/Ecircumflex/Edieresis/Igrave/Iacute/Icircumflex/Idieresis/Eth/Ntilde/Ograve/Oacute/Ocircumflex/Otilde/Odieresis/multiply/Oslash/Ugrave/Uacute/Ucircumflex/Udieresis/Yacute/Thorn/germandbls/agrave/aacute/acircumflex/atilde/adieresis/aring/ae/ccedilla/egrave/eacute/ecircumflex/edieresis/igrave/iacute/icircumflex/idieresis/eth/ntilde/ograve/oacute/ocircumflex/otilde/odieresis/divide/oslash/ugrave/uacute/ucircumflex/udieresis/yacute/thorn/ydieresis]/Type/Encoding>>^Mendobj^Mxref^M
0 2^M
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29 6^M
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Thanks for helping me :-)