You can go back to requiring home assignments be written by hand. It won't completely fix the AI issue, because you can still ask ChatGPT and then rewrite it, but it helps because it's very tedious and time consuming, so the benefit is much lower.
If that is not enough, we may have to stop grading take-home papers. Which is a good idea anyway.
If that is not enough, we may have to stop grading take-home papers. Which is a good idea anyway.