Identify Berry or Teal first
Open Settings and inspect the first item. Xumo’s current help identifies Closed captions as its Berry example and Picture and sound as Teal. Use the matching help section rather than applying a timer value from an unrelated screenshot.
This matters because the source describes different no-signal behaviour: Berry can turn off after fifteen minutes on HDMI, Composite or Antenna without a signal, while Teal describes five minutes for HDMI or Composite. These values should stay attached to their interface and input scope.
Separate inactivity from the missing input signal
Xumo describes a default eight-hour inactivity shutdown as a separate preference. In Berry it uses Auto-off under Device settings and Power preferences; Teal uses Auto standby under Startup and standby. Its no-signal exception remains even when that long inactivity setting is disabled.
Observe whether the external box or player went to sleep before the television switched off. If the input already showed no signal, the television may be responding to that state rather than interrupting a valid video session. Record the order of events and selected HDMI port. Also note whether a separate sleep timer was set for that session.
Report the actual sequence
For a controlled comparison, use an existing permitted source that remains active and note whether the unexpected shutdown still occurs. Avoid changing both source sleep settings and TV standby preferences at once, since that hides which condition changed the outcome.
If the TV shuts down while it continues receiving an active picture, record the model, interface, input and elapsed time. That is different evidence from a documented no-signal timeout. Checking the distinction before a factory reset can preserve your application logins while giving the manufacturer a more specific power-behaviour report.