@Gael I saw an error in a previous screenshot. I think there is an issue between russian Windows / myrobotlab and chrome.
WebkitSpeech send incomprehensible characters to java function onRecognized.
I have set my Windows to russian and this is worky. So this is related to deeper characters encoding issue, caused by the operating system. I need the log .

can you reproduce the problem : say something to the robot , and send us myrobotlab.log after that .
Waiting the fix, you can use an international Windows ( with russian language config )