StringDocument title does not render with error log

[rikashore]

I have the following code

const string sourceCode = "<{%>";

var doc = new StringDocument("code.eol", sourceCode);
var highlightRegion = new SourceRegion(new SourceSpan(doc, err.Position.Offset, err.Position.Line));

log.Log(new LogEntry(Severity.Error, new Text(err.Message), new HighlightedSource(highlightRegion)));

And I get the following output

But unlike the example, I don't see the code.eol get rendered. Is there something I'm doing wrong? Would appreciate some help