Here is a list of bugs I have encountered in Act 2 of the Definitive Edition:
1: Ifan Ben Mezd can't engage in dialogue with Roost Anlon at the sawmill. I’m pretty sure this bug is caused by interacting with one of the NPC’s around the sawmill area, as reloading to a save prior to interacting with some of them “fixed” the issue.
2: The salamander Xiuh at the Stonegarden won’t talk to you, even if you are a lizard with scholar and pet pal.
3: Ryker will start dialogue as if you have attacked or hit him, even when you have not.
4: The possessed dwarf in the “the sweet shackles of pain” subquest in the “the forgotten and damned” quest is bugged, as this sub-quest will remain unclosed after you banish the demon and set him free, thus rendering it impossible to completing the “the forgotten and damned” quest.