Since when is OpenAI able to detect if same password is used on another website?

Using same password on multiple website is worst thing someone can do, and you won't believe how many people are doing that every day.
You obviously have some malware on your computer and I would urgently reinstall OS and install fresh Linux, maybe even consider that everything you used is now compromised, including your bitcoin keys and financial stuff

Lummac2 stealer wont work on Linux.
Because - There are plenty of sites that will show many/these breaches and all the data in them has now been fed to open.ai. Simple teaching.