you hear things like this about every model. they're probabilistic and you can't trust them, although i doubt that kind of odd behavior would happen on low or medium effort levels. i find all of the models today pretty good at following instructions generally speaking. i'm sure you did /plan, but i rarely see it stray very far from the plan. Then again, I never walk away, since i'm always spinning up another task that can be done in parallel, and I don't let things run overnight because I'm not made of token cash (yet)