Please see the attached application for the repro case. Do check amx.css file under the cs folder. In amx.css file the font families are defined as following
font-family:'Helvetica Neue', Arial,sans-serif;

Due to RT-19678 issue, Helvetica Neue is not supported in WebView, that is understood, but the point is the font should not default to Times New Roman. The WebView should try to load the next available font which is Arial, and it is not doing that as you can see in the attached application.

So we cannot work around the Helvetica Neue issue by using the CSS fallback option. We cannot remove Helvetica Neue from font family as that is needed at RT and the fallback to Arial is needed for DT