Why has my baby stopped eating?

My son was doing great eating 3 puréed meals a day for around a month and then I started to introduce a bit of texture and now he won't eat. He seals his mouth shut, turns his head away and blows raspberries. Meals are turning stressful and I don't want to put him off food. I decided today to stop offering purées for a week and I've gave him solid food BLW approach but he won't put the food to his mouth. How can he go from eating 3 meals a day to suddenly not wanting any food. I know he's hungry cause after he will drink his milk.