Hi @jjaynes, I'm glad you figured it out. From what your description, please make sure the owner remove the Sesame from the app, un-register the account & clear cache, reset the Sesame before giving to another person.
If you lose your phone, you just simply log into your account from the Sesame app from the new phone.
Please feel free to reach out to us if you have any questions in the future. Thank you.