Hi @Trebor766,
Thanks for reaching out to the Roku Community.
We understand that you are encountering an issue when trying to set up your Roku Streambar through the ARC port on your new LG TV. I would like to suggest checking our Support page on How to set up your Roku Streambar with a non-Roku TV. This page provides detailed information and steps on how to properly set up your device, and it includes more details about the ARC port on your TV.
If after following the steps on the Support page and you're still encountering issues, don't hesitate to reach out to us again for further assistance.
Regards,
Nimfa