Cintiq stylus not working in Toon Boom Harmony Essentials

This is happening at a school where all the computers are on a network and are restarted and reset every night. The Cintiq stylus works properly in other programs like Photoshop and MS Paint, and the mouse will draw in Harmony, but when I press down to draw with the stylus in Harmony, nothing happens. Are there any common reasons why this might be happening?

It could be due to a bad Wacom driver or the setting inside the Harmony preferences,
on the “Advanced” tab. Try toggling the “Use QT Wintab Tablet Support” setting and
then relaunch the program.