I just picked up a Panasonic th-50fs500z from Cash Converters for the man cave. It has no aerial or box as I will only wifi for apps or mirroring.

When I am running Youtube or Netflix or screen mirroring after about 10 minutes the screen goes black with a warning box saying there is no signal, just as if I pressed the TV input button. I've looked through the settings and can't see anyway to stop this happening. I Thought that it might show this screen before going to standby after 10 minutes of no signal but this still happens after disabling auto standby.

Does anyone have any suggestions or is this an error and should i return it?

TIA