My guess is that it's some sort of electrical issue, since the rear sprayer works. You can hear the pump working when the rear switch is triggered. With the front, the wipers come on when the button is pressed, but these is no pump sound.Bad pump and/or crimped/broken washer fluid supply line. Those are my ideas.
Lastly of course would be an empty reservoir, but often best to check the most obvious stuff first. 😉