I have a blu-ray player in HDMI1 which is supposed to autoswitch. There is also an HDMI2 socket which doesn't, so make sure you are connected via the correct autoswitching HDMI socket.
Now for the curious bit. Ever since I've had the blu-ray player I have had problems with it auto switching on as well as auto switching off back to AV1. Recently I developed various health problems which resulted in a 7 week stay in hospital. I took the opportunity to have a new carpet laid and some decorating done. My son-in law organised everything including the removal and reinstatement of the TV and connected ancillaries. Unfortunately there were connection problems after he reinstalled it. As I am in a wheel chair I enlisted my Daughter's help and for the sake of simplicity disconnected everything and started again from scratch.
Strangely the problem blu-ray player now autoswitches every time and is quicker to boot up than it was before. I have no explanation as I have reconnected the player several times in an effort to rectify the intermittent fault.
After this episode I think that a poor connection on some other lead might lead to a problem with an appliance on a separate connection.
Anyway try disconnecting everything and starting again, maybe it will work for you.