I've had my B7A since March, but it recently started to have some weird behavior when it comes to recognizing input 2 vs input 4 on my TV.
The way I have it set up is as such:
Input 1 - PS4 Pro, directly plugged in
Input 2 - I'm using this for ARC to my LG SJ9 soundbar; my UHD Blu-Ray player is plugged into the SJ9's HDMI in so routes its signal THROUGH the soundbar back to Input 2
Input 3 - Xbox One X, directly plugged in
Input 4 - Nintendo Switch, directly plugged in
Now, input 2 and input 4 are the inputs in questions. Any time I turn on my Switch from Input 4, it turns on my UHD player as well and it "takes over" when it turns on and switches to input 2, the UHD player. I don't know why the UHD player wants to turn on any time I turn on my Switch, but this happens almost every time.
Now, I just had a problem yesterday where my TV no longer recognized input 2 for anything other than its ARC out from the TV to the soundbar -- it no longer recognized the UHD player that was routing through my soundbar. Powering on my UHD player, it automatically switched the TV to Input 4, but that returned a No Signal response as that's where my Switch is plugged on, and my Switch was not on and not producing a signal -- makes perfect sense that there was a No Signal response. Switching to Input 2 manually turned up a No Signal response as well.
At first, I thought it I was my TV that was causing this problem, so I factory reset it and then spent an hour and a half reconfiguring all my settings. It didn't fix the issue.
Then I unplugged both the sound bar and the UHD player, but I unplugged both at once and then replugged them in. The problem was fixed and my UHD player was reporting a signal from input 2 once again, but it restored the issue where turning on the Switch also turned on the UHD player. So once again, any time I turn on my Switch at input 4, my UHD player also turns on, then automatically switches to input 2 to display it.
Anyone know why this is happening? Anything that can be done to prevent it?
My two theories are:
1) The ARC signal from input 2 or the soundbar itself interpret input 2 and 4 as the same source.
2) The IR signal that's on most Switch controllers is telling the UHD player to turn on, and since the UHD player is also an LG product it communicates via Simplink to take precedence. I have tried blocking the IR signal or turning it away when I turn the Switch on and it still happens.