Thank you for your post.
Within the following Knowledge Base article, you will find a detailed description of What is “Trusted Devices” for your TeamViewer account?
To somehow "deactivate" Trusted Device, the Two-Factor-Authentication is recommended. All detailed information regarding Two-Factor-Authentication, you will finde here. After the activation, you just need to enter the Security Code that is displayed. No Trusted Device is needed anymore.
I hope, this could help and you can think about using the TFA :)
For further questions, please do not hesitate to contact us again.