Xpath working in online Xpath tester tools but not working in SoapUI

Dear Community Dwellers, I am trying to write an xpath in  open source SOAPUI version for the below xml.

<Group16DetailElectricity>
<Block16DetailElectricity title="Details" energyText="Energie type:" energyType="Elektriciteit" typeProductText="Type product:" typeProduct="Elektriciteit vast TK1" eanCodeText="EAN-code:" eanCode="5400000" distributionText="asdasd:" distribution="" contactNumberText="Gebruikt" periodText="Periode:" periodFrom="2015-01-01" periodTill="20222-09-20" averagePriceText="asdsa:" averagePrice="0.0494" averagePriceUoM="€/kWh" totalDescriptionText="Totaal afrekening elektriciteit:" totalExclVATText="Totaal" totalExclVATText2="(excl. BTW)" totalExclVAT="329.28" totalInclVATText="Totaal" totalInclVATText2="(incl. BTW)" totalInclVAT="398.43">
<Product typeProduct="Elektriciteit vast TK1" periodFrom="20222-01-01" periodTill="2222-ss-20"/>
<ConsumptionTable>
<ConsumptionLine consumptionType="Dag1" consumptionValue="1233" consumptionUoM="kWh"/>
<ConsumptionLine consumptionType="Dag2" consumptionValue="2222" consumptionUoM="kWh"/>
<ConsumptionLine consumptionType="Dag3" consumptionValue="3213" consumptionUoM="kWh"/>
<CosinusPhi consumptionType="Dag1" consumptionValue="1233"/>
</ConsumptionTable>
<TotalEnergyEssentTable tableDescription="Energiekost" periodFrom="2017-01-01" periodTill="2017-09-20" volumeText="Volume" unitPriceText="Eenheidsprijs" amountExclVATText="Excl. BTW" vatPercentText="% BTW" totalTable="329.28">
<TableLine tableLineDescription="Dag1" volume="1233.000" volumeUoM="kWh" unitPrice="0.04015" unitPriceUoM="€/kWh" amountExclVAT="49.50" vatPercent="21.00"/>
<TableLine tableLineDescription="Dag2" volume="3213.000" volumeUoM="kWh" unitPrice="0.04533" unitPriceUoM="€/kWh" amountExclVAT="145.63" vatPercent="21.00"/>
<TableLine tableLineDescription="Dag3" volume="1.000" volumeUoM="jaar " unitPrice="134.15000" unitPriceUoM="€/jaar" amountExclVAT="134.15" vatPercent="21.00"/>
</TotalEnergyEssentTable>
</Block16DetailElectricity>
</Group16DetailElectricity>

The xpath I wrote is working fine in all the online websites for xpath testing. Here is the piece if the code: Why i need Xpath? I want to extract the value of attribute - amountExclVAT based on the other attribute value (Dag1/Dag2/Dag3).

The xpath i wrote is - 

//Block16DetailElectricity/TotalEnergyEssentTable/TableLine[@tableLineDescription='Dag1']/@amountExclVAT

which doesnt work in SOAP UI and gives null response.

Though the below xpath 

(//@amountExclVAT)[1/2/3] works fine and i can see the result. 

But the issue with working Xpath is that the position of the Tableline can change with every new request and we want to map the values specific to the TableLineDecsription with the previous XML. So the working soulution is not handy in this solution.

My question is why my Xpath is not working in SoapUI and giving null error.

Any help is appreciated.

Thanks,

Ankush