Hope that you will read this.
Following is a script from web module, as you see that there are <h3>. TCF is a TStringList.
Anyway ts1 reproduce correctly, while ts2 does not displayed correctly.
ts := '이것이 한글 코드입니다';
ts1 := '<h3>[' + ts + '] ' + TCF.Values['title'] + '</h3>';
ts2 := Format('<h3>[%s] %s</h3>',[ts, TCF.Values['title']]);
Actually this is not easy to reproduce --- but it happen repeatedly on my specific program. System is Windows 10, Korean characters, Locale is Korean characters, but not set to use UTF-8 to display global languages.
Is it possible that something is done in format function? I'm using format widely and not suffering any problem in most cases. I suspect that it caused some problems only in web module.