xmltable projection producing errors or inconsistent results

Context:

Client Table

userid varchar(20)

docid number

record xmltype

say userid = A ; docid= 1, 2

First record has structure as below

<Sheet>

<UE>

  <deal>

    <metric>

      <detail>Code</detail> <facility_1> 123 </facility_1> <facility_2> 234</facility_2>

    </metric>

    <metric>

      <detail>name</detail> <facility_1> alpha </facility_1> <facility_2> beta </facility_2>

   </metric>

    <metric>

      <detail>value</detail> <facility_1> 222</facility_1> <facility_2> 333</facility_2>

   </metric>

      <metric>

      <detail>keep </detail> <facility_1> No </facility_1> <facility_2> Yes </facility_2>

   </metric>

  </deal>

</UE>

</Sheet>

Second record has structure

<Sheet>

<UE>

  <deal>

    <metric>

      <detail>Code</detail> <facility_1> 678 </facility_1> <facility_2> 890 </facility_2>

    </metric>

    <metric>

      <detail>name</detail> <facility_1> first </facility_1> <facility_2> second </facility_2>

   </metric>

    <metric>

      <detail>value</detail> <facility_1> 444 </facility_1> <facility_2> 555</facility_2>