GPT 3.5 is a lot worse than GPT 4
It should shock no one to learn that Open AI's newer, better language model is an improvement over the old one, but if you aren't an active user of any of this newfangled AI stuff, it can be easy to lose track of just how much better things are getting and how quickly.
If you subscribe to GPT Plus, ChatGPT will also implement the ReAct pattern for requests it thinks can be formalized, which is one way to mitigate hallucinations.