When importing such an XML file into QGIS version 3.34, an object attribute (dientZurDarstellungVon) is not imported. There was no problem with this XML import in the previous version. The XML structure is correct. I suspect the issue is related to xlink declarations, which may not be supported by QGIS version 3.34. Unfortunately, I have not been able to find a solution. I am sharing my problem with you and would be grateful if someone could help me.
       <AP_PTO gml:id="DENIAL1100000JEj">
          <gml:identifier 
           codeSpace="http://www.advonline.de/">urn:adv:oid:DENIAL1100000JEj</gml:identifier>
          <lebenszeitintervall>
            <AA_Lebenszeitintervall>
              <beginnt>2022-07-27T15:17:18Z</beginnt>
            </AA_Lebenszeitintervall>
          </lebenszeitintervall>
          <modellart>
            <AA_Modellart>
              <advStandardModell>DKKM1000</advStandardModell>
            </AA_Modellart>
          </modellart>
          <position>
            <gml:Point gml:id="DENIAL1100000JEj_G0" srsName="urn:adv:crs:ETRS89_UTM32">
              <gml:pos>445161.836 5889225.500</gml:pos>
            </gml:Point>
          </position>
          <fontSperrung>0</fontSperrung>
          <skalierung>1</skalierung>
          <horizontaleAusrichtung>zentrisch</horizontaleAusrichtung>
          <vertikaleAusrichtung>Mitte</vertikaleAusrichtung>
          <art>Strasse</art>
          <dientZurDarstellungVon xlink:href="urn:adv:oid:DENIAL11000006uR" />
          <drehwinkel uom="urn:adv:uom:rad">5.5998853</drehwinkel>
        </AP_PTO>