Baby Food Strike?

As of three weeks ago, my 8.5 month old baby refuses to eat any of his purées - it doesn’t matter the flavor, temperature, consistency - the kid clamps his mouth shut and shoves the spoon away. I’ve been trying to give him finger foods, but he’s refusing that too. I’ve tried toast, banana, avocado, eggs, soft carrots, puffs (basically dissolvable Cheerios), yogurt bites...nothing. I’ve tried eating with him, using a “grown up” spoon, trying to put the purée on his table so he can eat with his hands...NOTHING. We’re back to a formula only diet. 🙄 Any tips on how to get this kid to eat again?