https://ttlc.intuit.com/community/taxes/discussion/i-want-to-delete-my-account-i-made-with-mint-but-am-not-able-to/00/142257
I can confirm I also have this issue. I've been more paranoid about which firms have my data, and after confirming individual login password is correct (via a manager) and resetting it forcefully - it will not allow you to complete the workflow to delete your account. It always resets to "wrong password."
Interesting dark pattern indeed.