Establish that the issue belongs to the HDMI path
Confirm that the television’s own menus and an existing app can display, then select the HDMI port connected to the older device. Record whether the TV reports no signal, shows a blank picture or receives video without audio. Those observations describe different stages of the external path.
Xumo’s help starts with the cable and a power cycle of the TV and source device. Keep the connection order and original input setting in your notes so a later compatibility change can be compared against a known baseline. Do not change streaming-app account details for an HDMI-only symptom.
Use the matching compatibility control
Xumo describes older-device incompatibility with its higher-speed Standard settings and provides a Compatibility route. Berry places HDMI compatibility under Antenna and inputs for the selected HDMI number. Teal uses Connected devices, HDMI inputs, Older device compatibility.
Apply the documented choice to the input carrying the older device, then test the same source again. Avoid changing an unrelated port used by a newer player. A compatibility setting is a link configuration; it is not proof that the source can produce every resolution or protected format supported elsewhere on the television.
Keep the result and trade-off visible
If the picture returns, record the working setting and source model. Preserve the original value so the input can be reassessed if its attached device changes later. Do not describe the result as a general improvement for every HDMI source.
If it remains blank, provide Xumo and the source maker with both models, interface version, port, cable comparison and compatibility result. The unchanged working app picture is useful context because it narrows the fault to an external source path rather than the entire television display or network connection.