This could be a total longshot, but if you have a set of devices with HDMI cables and CEC enabled, if a cable fails or a new device comes in that isn’t doing proper termination, it can affect the whole network.

Maybe try unplugging all devices, restarting the TV, then adding them back one by one and see if it still happens.

It can totally be a hardware or firmware issue on the TV side, but at least, this is a cheap and easy test.