Hi Raphael,
The XAUUSDx you are referring to is just the name of the chart. The historical data (candles) are still the XAUUSD pair. As long as you see a blue hat in the upper right hand corner of the chart then the Expert Advisor (robot) is working properly. If you just installed the Expert Advisor on the chart within the last day or two then give it another day for the Expert Advisor to open a trade.
Alan,