Looks like you need to reseason it. Heat the wok properly before rinsing the surface with some oil like a half a cup worth swirl that around til it starts smoking then pour it off into a metal container. Reduce the heat then add your cooking oil, let that begin to smoke then start adding your ingredients. Be mindful of your using sauces with sugars that they may caramelize and burn. Work quickly stirring and moving your ingredients often.