honestly understandable. Astarion has only ever made it into my party ONCE in my handful of playthroughs throughout early access and release.
Didn't really want to use him during my current playthrough (why tf am I still in Act 1 I have like 100 hours logged) so when I picked him up I was like "just go to camp bro"
Tell me why he has the nerve to complain about Karlach and whatnot in camp after I let him do the succ the one time. Bro shut the hell up you are just hanging out in camp keeping watch on my valuables (and Scratch) while me & my REAL comrades (Shadowheart, Gale, and Lae'zal) go gallivanting around. Vampire twink begone, I have Invisibility prepared on Gale and also have a ring that lets Lae'zal cast invisibility - I need you for NOTHING not even thievery. Oh there's something nearby I can't grab? Githyanki Jump and/or Mage Hand. what use are you, you vampire twink, besides doing the succ on enemies. (don't ask me how many times my party has failed to hit someone with an arrow)
Anyways Astarion disliked that.