Opus 4.8 prioritizes system-prompt behaviors over my actual prompt and ignores explicit "don't do X" instructions

Plan: Claude Max ($200/mo) · Model: Opus 4.8 (Claude Code)

I'm frustrated and I'm close to unsubscribing from Claude Max $200.

Opus 4.8 keeps mentioning unrelated stuff even when I tell it not to. It focuses on the stuff the fucking system prompt tells it to focus on instead of the actual task from my prompt. The session always derails from the actual task because the fucking system prompt tells it to focus on stuff it chooses to focus on.

My prompt should come first. Instead the system prompt is in the driver's seat and my actual instructions get ignored. When I say "don't do X," it should not do X. Fix the instruction-following on Opus 4.8 — explicit user instructions need to override the system-prompt defaults. This is the difference between me keeping Max and cancelling.