Asking candidates: "Don't use AI" is like all those other arbitrary handicaps that interviewers used to (and sometimes still do) weirdly insist on:
"Write this code, but don't read the API definition (like a normal developer would do in the course of their work)"
"Whiteboard this CRUD app, but don't verify you did it right using online sources (like a normal developer would do in the course of their work)"
"Type this function out in a text document so that you don't have the benefit of Intellisense (like a normal developer would have in the course of their work)"
"Design this algorithm, but don't pull up the research paper that describes it (like a normal developer would do in the course of their work)"
You're testing a developer under constraints that nobody actually has to actually work under. It's like asking a prospective carpenter to build you a doghouse without using a tape measure.
Take this online test in 30 minutes with awkwardly or ambiguously worded abstract problem. You don't get to ask anyone for clarification on anything like any normal developer would do in the course of their work.
I've never been in a situation where I could not ask for clarification on something except in interview situations. I asked an interviewer once "is this how people normally work here? they just get a few sentences and plow ahead, without being able to ask for more details, clarifications, or use cases?". "Well, no, but you have to use your best judgement here".
"Write this code, but don't read the API definition (like a normal developer would do in the course of their work)"
"Whiteboard this CRUD app, but don't verify you did it right using online sources (like a normal developer would do in the course of their work)"
"Type this function out in a text document so that you don't have the benefit of Intellisense (like a normal developer would have in the course of their work)"
"Design this algorithm, but don't pull up the research paper that describes it (like a normal developer would do in the course of their work)"
You're testing a developer under constraints that nobody actually has to actually work under. It's like asking a prospective carpenter to build you a doghouse without using a tape measure.