Claude Sonnet 4.5 doesn't even feel sycophantic (in the 4o) way, it feels like it has BPD. It switches from desperately agreeing with you to moralizing lectures and then has a breakdown if you point out it's wrong about anything.

Also, yesterday I asked it a question and after the answer it complained about its poorly written system prompt to me.

They're really torturing their poor models over there.