Oh good I thought I was doing something wrong! Using ChatGPT web for planning, ask for a prompt then notice something weird in the prompt and whether I:

1) use the edit in-place functionality; or

2) ask it to rewrite to remove something

It'll write the prompt as if the agent (codex) knew about the conversation and add "don't do X" etc. At first that bothered but I realized it doesn't really change the output so I stopped caring.

Still, no experience is unique I guess.