Every time my UN65JS8500 turns on, it forces the AVR to switch to the ARC input, even though I haven't loaded any smart apps yet and actually want to have it go to the last input it was on (the Xbox One).
TV HDMI 4 (ARC) <--> Yamaha TSR-7810 (Costco RX-V781) HDMI 1 OUT
Xbox One S --> Yamaha HDMI 1 IN
TiVo --> Xbox One S
"Xbox On", Xbox powers on the TV (and through it receiver thanks to CEC), and once the TV comes on, I see the video from Xbox One (and in turn, the TiVo). The audio source switches to the TV, but I still get video from Xbox/TiVo because reasons. Sometimes, I get brief audio before the TV forces the Yamaha to switch to "AV 4" (the default name for ARC in), but not always. I have to pick up the Yamaha remote and manually select HDMI 1 to get audio back.
I could just use Toslink from the TV to the AVR, but I was hoping that switching would work correctly, for WAF. In the bedroom we have a Vizio M43-C1 and Vizio soundbar and it switches correctly and then when done with the TV app switches back to the soundbar's normal HDMI input (which is also an Xbox One).