Set the intended startup result
Decide whether you want Home, the last-used input or one fixed HDMI port. Those choices have different results after a household member changes inputs. For a fixed external player, note the physical HDMI number so the preferred choice points to the port actually in use.
Follow the matching manufacturer steps and then test the next power-on. Xumo says its default-input choice takes effect when the TV is turned on after the change. An immediate manual input switch during the current session is therefore not the complete test of that preference. Test after the current session ends.
Keep signal and startup selection separate
If the correct HDMI input opens but shows no signal, the startup preference has selected the intended destination; investigate the attached device’s power and connection next. If another input opens, record that behaviour separately from whether the external player itself works.
For support, include interface version, preferred option, connected HDMI port and what appeared on the next startup. Also note whether the last-used input was deliberately selected rather than a fixed port. This gives Xumo a clear setting/result pair and avoids resetting applications to solve an input-selection question.