Using the Speechsynthesis component / FNC ExecuteJavascript.
"speak" method does not run anymore after a TrySetStyle at run-time, it seems there is a problem with ExecuteJavascript. That probably concerns all ExecuteJavascript calls.
Please provide a sample code snippet to demonstrate exactly what you are executing. Is this a runtime style you apply? It could be possible that applying the style needs a reinitialize from the control. Can you try calling TMSFNCWXSpeechSynthesis1.ReInitialize;