Frontier models sabotaging local AI implementations?

Excerpt

For a few days I've been working on creating a custom local-only harness for some work related research using Codex / GPT 5.6 Sol and the model feels not only dumber than usual, but straight up counter productive. It keeps adding unnecessary guardrails for the local agents, removes tools that I clearly specified I want them to have and always drifts from the original requirements. I need to ask it to change things multiple times, which ends up on some over-complicated final product. This is not