You may need to check your brokerage to see if they are allowing third-party access. Although the following Help Article is for Schwab, it is possible that your brokerage has restricted TurboTax's access to your statements unless you grant consent, and you might need to do something similar to what is described here: 1099 Import Issues.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"