Hello!
This is related to this issue.
It is recommended for project configuration files to be stored in the Assets folder for Unity projects. The Provider.Checkout API may have happened to work with files outside of Assets in the past, but other functionality (Unity Collaborate) does not. We are trying to update our documentation.
Could the GvhProjectSettings.xml file be moved to the Assets folder? Unity would then recognize the file, which could be used by other systems.