In general, for debit card transactions at ATMs or at merchants, consumers must opt-in, or agree up front, that the bank can charge you an overdraft fee for any debit card transaction that overdraws the account. If you don’t opt-in, you can’t be charged a fee. However, your bank may refuse your purchase if it will overdraw your account.
Did you specifically ask the bank to disable overdraft protection? They can be really weaselly about turning it off. They HAVE to turn if off. By law.
https://www.fdic.gov/resources/consumers/consumer-news/2021-12.html