I'd suggest that it would be that your codec detects that a touch navigator has been disconnected, and that it should have one connected, so it is reporting it as an issue, and that is stopping it from going to standby.
I haven't tested this myself, but you could try changing Configuration > Peripherals > Profile TouchPanels to 0 (instead of the default "Auto", or whatever setting you have currently configured).
This setting is used to define the number of Cisco touch controllers that are expected to be connected to the device. This information is used by the device's diagnostics service. If the number of connected touch controllers does not match this setting, the diagnostics service will report it as an inconsistency. Setting it to 0 will stop it trying to detect the presence of a Navigator and will hopefully fix your issue.
Wayne
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