Opus 5.5 has been terrible for me for the last week - so seems like they got the memo.
Luckily switching is super easy so I'm now back to codex (and hopefully carbon soon)
I hope it's not their next model (it looks like it might be) I did an investigation with some battle data here: https://micjm.com/blog/get-ready-for-fewer-opus-5.5-em-dashe...