So, other things just about Astarion's story are bugged too.
When you come up to him and he's supposed to be tracing his infernal scars with his fingers, he just awkwardly stands there facing you while saying "a line...and one two tree dots..." and then robot moves to the position he's supposed to.
I've never had an issue with that scene before and now it looks weird. The rest of the scene plays out like it's supposed to but it is really strange to have him facing you and saying what he does...