Since you mentioned it happens specifically at the shrine or when picking up the book at the Blighted Village, I assume the same will happen if you approach Selune's statue in the Owlbear Cave, because these are all triggers for Shadowheart's conversation.
So it seems her conversation is bugged in your game, which verifying might fix. Try to switch the APIs too. If you are on Vulkan, try DX11 and vice versa.
