AppleTV on LG webOS "Couldn't Load Video"

This is a strange problem. I have tried everything that I have found in Google searches on this issue.

If I play any AppleTV content, it briefly plays the Apple intro, then tries to load the stream. But this fails every time, and it shows the error "Couldn't Load Video / Check your internet connection then try again." What is strange, is this only happens when the Apple intro is played. If I play an episode that is already in the middle (so no intro sequence) it plays fine. Everything else works. As noted, I can play episodes that are already in progress. But I can't play anything from the beginning. To be clear, my internet connection is fine. I can play everything in my Apple TV library. Netflix, Prime, Hulu, Youtube, Youtube TV, Disney+, Max, and Peacock all work. LG channels work. It is just shows on Apple TV, that play the Apple TV intro sequence.

What I've tried:

• Checked that the TV has the latest software
• Restart TV
• Delete & reinstall the Apple TV app
• Unplug and plug in the TV
• Restarted my Verizon FIOS router
• Checked network settings on my router
• Tried with IPV6 on then back off
• Tested on wifi
• Tested on wired ethernet

None of this makes a difference- all other streaming services continue to work, the Apple TV app fails.

This is a new LG TV from Costco:

Model 65QNED85TAA.BUSELKR

WebOS version: webOS24 / 9.1.0-46