"Reasoning" has absolutely tanked since July 13th updates: chatGPT, Codex, app & Web - across the board.

Eg, from the horse's mouth:
"Even after repeatedly acknowledging that accuracy mattered more than speed, my behaviour remained shaped by the urge to provide the next usable artefact quickly."

A previously stable process / Development workflow has become practically unusable. Basic AGENTS.md and even direct instructions flagrantly ignored. Regression applies to both new 5.6 model, and the previously trustworthy 5.4

Example after example of the 'assistant' being incredibly thick in the simplest of communications, dangerously blase, or just plain ignoring instructions. chatGPT / Codex is no-longer a 'virtual-assistant', it is a 'virtual-intern'... and an actual pain in the arse!

Blatant disobedience of instruction:
<img width="689" height="344" alt="Image" src="https://github.com/user-attachments/assets/84ea740e-43d1-498e-9353-5ce271d19a7d" />

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A typical (disastrous) user experience:

<img width="1280" height="690" alt="Image" src="https://github.com/user-attachments/assets/638ddb92-c215-49ee-a245-bc40082b4ebe" />

<img width="1280" height="690" alt="Image" src="https://github.com/user-attachments/assets/3f9ba6dc-11c6-4a8f-ba3a-140408e9bfcf" />

<img width="1280" height="690" alt="Image" src="https://github.com/user-attachments/assets/04b3e81c-b277-4139-be76-31cf9a904e57" />

<img width="1280" height="690" alt="Image" src="https://github.com/user-attachments/assets/d36f51a1-b3d7-459e-8e24-f0d6a71dd35a" />

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Temporal confusion and Doctor Who level rewriting of history:

<img width="1280" height="684" alt="Image" src="https://github.com/user-attachments/assets/5a5cc657-2a6e-46b7-8d32-4b59a3313317" />

<img width="1280" height="684" alt="Image" src="https://github.com/user-attachments/assets/b143b6c9-ec44-4e4e-aa78-7cc12f57e2cc" />

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