AV Receiver will not display signal to TV's HDMI1 (ARC) inpu

[Guest]

I have an LG 55LA5500 TV and a Pioneer VSX-1122 receiver. I have an Xbox, PS4, and a Cable box connected to my receiver. When I connect my receiver to my TV's HDMI1, it will not transmit any signal to my TV. However, HDMI2 and 3 work absolutely fine. However, when I connect my Xbox or PS4 to HDMI1, they work fine.

Why is my AV receiver refusing to transmit video to the HDMI1 input? Is it because of the ARC feature on the HDMI1 input? The weird thing is, the ARC feature works when I do connect to HDMI1 and use Smart TV features.