If you are unable to control the device using the XTouchApp,
Make sure that software and firmware versions are up-to-date.
Exit the Xilica Designer software then restart the XTouchApp on your device. The device should now be responsive.
X Series processors (XP and XD) can only accept 1 TCP connection at a given time.
This means that it all depends on how many controlling devices (such as XTouchApp, Xilica Designer) are running at the same time. Each one counts as 1 TCP connection to the X Series processor.