One thought. If you accidentally saved the 2020 file with a password then if you look at my screenshot above there is a checkbox (Remember password - save to keychain) as default. So if that was not unchecked then it can be password protected but keychain is entering it for you when you open with the 2020 program.
Use Utilities Keychain Access.app to view the login keychain and see if there is a Turbotax keychain. If there is then you can double click on it and view the password.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
