Json Configuration custom IFileProvider stopped working for .NET 5.0

We built support for encrypted appsettings.json in our app by using encrypted xml support built into .NET. To integrate this we use JsonConfigurationSource with a custom File Provider to return custom IFileInfo with CreateReadStream overriden to decrypt file. Like code below:

public static IConfigurationBuilder AddJsonFileProtectedByEncryptedXml(this IConfigurationBuilder builder, string path, bool optional = false, ILoggerFactory loggerFactory = null)
{
    var source = new JsonConfigurationSource
    {
        Path = path,
        // Specify file provider to use so that JsonConfigurationSource can read the decrypted form of config file.
        // Note config file does not need to be XML, only the container that contains the config file should be XML.
        FileProvider = new EncryptedXmlContainerFileProvider(loggerFactory),
        Optional = optional
    };
    builder.Add(source);
    return builder;
}

After upgrading to .NET 5.0 this stopped working.

Workaround: return null from PhysicalFilePath in custom IFileInfo. https://github.com/dotnet/runtime/blob/9b9303678de0f5573fef580f3f52404ea0a20dd4/src/libraries/Microsoft.Extensions.Configuration.FileExtensions/src/FileConfigurationProvider.cs#L87