Apple TV 4 keeps restarting (tvos 9.0.1)

I bought a 64GB Apple TV 4 a couple of weeks ago and jailbroke it. I then noticed that intermittantly, the screen would go white and then take me back to the main menu. I couldn’t find any pattern to when or why it would do it, but presumed it was due to the jailbreak. I tried 2 different hdmi wires and 2 different tvs and it kept doing it over and over again. This Apple TV was on tvos 9.0.0.

Today, I took it back to Argos and got a new one, got home and this one is doing the exact same thing straight out of the box. I have not downloaded anything to it yet. All I have done is connect to wifi and go through the initial setup. This Apple TV is on 9.0.1.

The fact that both are doing the exact same thing despite being on a different os, suggests it isn’t a firmware issue. The tests with different hdmi wires and tvs suggests that neither of those are the issue either, so I am completely lost.

I just rang Apple Support and they have suggested that I take it back to Argos for yet another return or to bring it into an Apple store so that they can take a look at it, but the nearest store is over an hour away so I’d rather not do that if I can avoid it and the first thing they will try is updating the firmware anyway which will mean no jailbreak.

I have tried searching the internet to see if anyone else has had this problem, but all I can find are people on older devices or older firmwares.

Any help or assistance would be greatly appreciated? Cheers. Trevor