Code coverage visualisation in Merge Requests

To flesh out my issue some more, here are some details.

GitLab Version: 13.12

Cobertura file snipped with no path alterations:

<?xml version="1.0" encoding="utf-8"?>
<coverage line-rate="0.8332999999999999" branch-rate="0.75" version="1.9" timestamp="1666643932" lines-covered="5" lines-valid="6" branches-covered="3" branches-valid="4">
  <sources>
    <source>C:\</source>
  </sources>
  <packages>
    <package name="TestLib" line-rate="0.8332999999999999" branch-rate="0.75" complexity="4">
      <classes>
        <class name="TestLib.MyTestClass" filename="b\Ventilation\sandbox\code-coverage-spike\TestLib\MyTestClass.cs" line-rate="0.8332999999999999" branch-rate="0.75" complexity="4">
          <methods>
          .............

Cobertura file with path alteration (no trailing slash on source):

<?xml version="1.0" encoding="utf-8"?>
<coverage line-rate="0.8332999999999999" branch-rate="0.75" version="1.9" timestamp="1666639721" lines-covered="5" lines-valid="6" branches-covered="3" branches-valid="4">
  <sources>
    C:\b\Ventilation\sandbox\code-coverage-spike
  </sources>
  <packages>
    <package name="TestLib" line-rate="0.8332999999999999" branch-rate="0.75" complexity="4">
      <classes>
        <class name="TestLib.MyTestClass" filename="TestLib\MyTestClass.cs" line-rate="0.8332999999999999" branch-rate="0.75" complexity="4">
          <methods>
          ............

Cobertura file with path alterations, plus trailing slash on source:

<?xml version="1.0" encoding="utf-8"?>
<coverage line-rate="0.8332999999999999" branch-rate="0.75" version="1.9" timestamp="1666644321" lines-covered="5" lines-valid="6" branches-covered="3" branches-valid="4">
  <sources>
    C:\b\Ventilation\sandbox\code-coverage-spike\
  </sources>
  <packages>
    <package name="TestLib" line-rate="0.8332999999999999" branch-rate="0.75" complexity="4">
      <classes>
        <class name="TestLib.MyTestClass" filename="TestLib\MyTestClass.cs" line-rate="0.8332999999999999" branch-rate="0.75" complexity="4">
          <methods>
          ................

The relevant portion of my gitlab-ci file looks like this:

  artifacts:
    name: Unit Test Results
    paths:
      - $CI_PROJECT_DIR\cobertura\*\coverage.cobertura.xml
      - $CI_PROJECT_DIR\junit\*-junit-test-result.xml
    reports:
      cobertura: $CI_PROJECT_DIR\cobertura\*\coverage.cobertura.xml
      junit: $CI_PROJECT_DIR\junit\*-junit-test-result.xml      

Also, the artifacts are successfully uploaded at the end of the job.

It would be very helpful to have some guidance on what I am doing wrong here, or what the underlying issue is.