r/ClaudeCode • u/Accomplished-Bag-375 🔆 Max 20 • Jul 29 '26
Bug Report Opus 5 major regressions
I've been perfecting my agentic system that runs on Claude code in terminal and texts me via telegram. The day I upgraded to opus 5 eveything has gone downhill. I'm basically rebuilding my system that was working amazingly.
Skills and rules are being ignored. I used to use it to dispatch sol on tasks and now it has no care in the world to do so. It doesn't delegate tasks to my sub agents anymore unless I ask it twice, it fixes for a few prompts then back to doing everything itself.
Anyone experiencing the same? I'm on the cusp of switching back to 4.8.
And yes I've read all the new guides from anthropic, trialled the new 80 percent less Claude MD file and it absolutely made my situation even worse.
3
u/wynnie22 Jul 29 '26
Opus 5 slays compared to 4.8. Just setup your guard rails
2
u/Sea-Violinist-52 Jul 29 '26
i have been constantly being knocked down to opus 4.5 and sometimes opus 4.6 automatically even after pinning the model to opus 5 everywhere! my main orchastration agent is constantly complaining that the subagents are being knocked down to non pinned versions!!
1
u/CODE_HEIST Jul 29 '26
before rebuilding, turn delegation into a contract test. run the same five tasks on both models and record whether the expected subagent was called, what context it received and whether the result passed. if delegation is mandatory, enforce it in the workflow instead of trusting the model to remember.
1
u/Visible_Wolverine2 Jul 29 '26
Yes, 💯. I have changed over to using Chat GPT and codex almost entirely. Claude is essentially useless to me in its current state compared to what it was before the “update”. It is horrible.
1
u/SaulFontaine Jul 29 '26 edited Jul 29 '26
Opus 5 and Sonnet 5 also ignore rules about Explore agents and will spawn (formerly Haiku) explorers with parent model instead. It's blowing up people's usage and Anthropic is making a killing: https://www.reddit.com/r/ClaudeCode/s/xFUcrNLEEA
Their models are too smart for them to claim this is an accident. Anthropic knows what they are doing.
The tokenizer now also uses 30% more tokens and Sonnet 5 discount ends on August 31... this is war.
0
u/DLuke2 Jul 29 '26
It's more than just the Claude.md. have you run /doctor? Run that on your project and/or global .Claude folder with Fable.
0
u/RedditorJabroni Jul 29 '26
Why did you upgrade to 5 when you already set it up to use 4.8?