Unexpected coverage changes that we cannot explain?

Description

We’ve recently adopted CodeCov, sending reports generated with OpenCover via AppVeyor. We’re seeing a lot of unexpected coverage changes that we cannot explain. We need some help determining whether there’s a problem with our configuration, with the reports being generated by OpenCover, or with CodeCov.

The “Diff” reported by CodeCov accurately portrays the only difference in the code, but the “Changes” and “Files” sections contain many unexpected changes that we cannot explain.

The PR branch was rebased against the develop branch prior to submittal and changes from develop are minimal. Code coverage changes were expected for Utilities/Versioning.cs but unexpected changes are being reported in 23 unrelated files.

appveyor.yml and .codecov.yml are the same in both branches.

Repository

CodeCov branch comparison

https://codecov.io/gh/EDCD/EDDI/compare/develop...additional-versioning-tests/diff

Versions

Firefox browser, Windows 10.

Additional Information

We’ve generated the code coverage files locally and tried to compare the results, but the locally generated reports do not seem to indicate changes to the same files identified by CodeCov. The locally generated reports are available at the following dropbox links: https://www.dropbox.com/s/y0v3ebtjezssgmn/coverage-develop.xml?dl=0 and https://www.dropbox.com/s/1asqzh9t8vwjtlw/coverage.versioningtesting.xml?dl=0.

Thank you for your time!
Tkael