What do you believe was incorrect? I asked Chat GPT 3.5 and 4 this question verbatim, seems they both gave the correct answer: it is taxable income. 4 was very thorough. 3.5 not so much.
This is the answer I got: “Interest earned in Canadian Registered Retirement Savings Plan (RRSP) accounts is generally not taxable income in California for state tax purposes. California does not typically tax income earned in foreign retirement accounts like RRSPs. However, it's always a good idea to consult with a tax professional or accountant for personalized advice based on your specific situation.”