Hello! @prburnett
Welcome to the LastPass Community.
We truly apologize for the problem; it sounds weird that the account recovery does not request to change the master password, by the time you start the forgot master password and right after you get the verification code you will be required to change the master password and then log in using the new combination.
You can manually change your master password by going to account settings, general tab, change master password.
Please let me know if you need additional help.
Greetings!
Verlaine | Customer Care