LG C4 HDMI 2 ARC Issue

So I have a brand new 2025 C4 for about a month now. I have an Apple 4K V1 running to my LG SJ9Y (2017) sound bar, and then the sound bar to HDMI 2 ARC.

It had been working fine this whole time, then all of a sudden, getting No Signal to the TV.

Ran through all the troubleshooting I can do, check cables, unplug TV, soundbar, Apple TV etc. and for the most part, it’s not working. The signal randomly comes back, and works fine with YouTube TV or YouTube, but crashes as soon as I try to put something Dolby Atmos from Netflix or Prime.

Now here’s the kicker, change the connection to a non ARC HDMI port like HDMI 1, no problems. Getting signal and even getting Dolby Atmos sound.

I even plugged the Apple TV directly to HDMI 2 and was getting Dolby Vision and signal no issues.

Reconnect everything back to HDMI 2, put on Netflix and picture goes black, soundbar keeps repeating Dolby Atmos a few times and then eventually NOT SUPP.

So trying to figure out if the HDMI ARC port is defective on the TV, or if it’s because I’m using an older LG soundbar and Apple TV model that just aren’t compatible with current sound and audio formats?

Any thoughts here?