15-5: TeamViewer 15 Host Windows • 15.1.3937 ... Under Advanced > General advanced settings, set "Check for new version" to "Never" and set "Install new versions automatically" to "No automatic updates"..... One good reason to block updates: As of Feb 2022, the current version (15.26.4) requires creation of a TeamViewer account to set up unattended access. An account is free, but it's an unnecessary hurdle.
15-6: TeamViewer 15 Host Mac ... In settings, disable checking for new versions and disable automatic installation of new versions.