Idk what triggers it, maybe getting to the grove. I went a different way by jumping over some fire, so I had already done the fight at the grove, and made it to the goblin camp with just Shadowheart. But every fight was so hard that I took to the internet and discovered I was supposed to meet her and Astarion. I went back and Astarion was there, but she was gone. Now I finally met Karlach and Wyll too, but defeated the entire goblin camp first, and failed the fight at Grimforge before finding them. I’ve made it all the way to level 6 without a tank.