Sure enough, 32 out of the 35 students across two classes simply copied the question, pasted it into a chatbot, then copy and pasted its output into the answer window.
That's an insanely high proportion. I don't think I've ever cheated on an exam or assignment, so the concept seems kind of weird to me.
I wonder if some of the remaining people used AI but then reviewed the output and removed the weird stuff, or if they wrote it themselves.