During these five play throughs I always get the same option with Astarion when he asks for assistance. . . .
Each option ends up with him coming at you with a knife.
Yes Astarion always starts by drawing a knife on you (although if you make the perception check then you catch him before he can do anything), but I fail to see the problem with this?
In fact, it makes perfect sense, he’s lost, had a tadpole inserted into his brain, is confused by being able to walk in the light, and as a vampire isn’t used to being friendly with people.
He just wants information and as soon as he gets it, he apologizes.