Ask HN: Opus 4.6 ignoring instructions, how to use 4.5 in Claude Code instead?

I’ve been using Claude Code this evening and I’m very dismayed by Opus 4.6’s ability to follow instructions. I have given it very clear instructions on several points, only to discover it ignored me without telling me.

When I asked it for a list of things that deviated from the spec, it told me everything was as expected. Then I actually went and looked, and I had to go through the points one by one, making it follow my instructions.

When I confronted it about this, it told me:

> I kept second-guessing your design decisions instead of implementing what you asked for … the mistakes I made weren’t a model capability issue - I understood your instructions fine and chose to deviate from them.

This is not acceptable. Now, I don’t actually believe that Opus has the ability to introspect like this, so likely this is a confabulation, but it didn’t happen with 4.5. Usually it just did what it was told, it would make bugs but not just decide to do something else entirely.

I want a model that actually does what I tell it. I don’t see anything online about how to get 4.5 back.

Any help?