Welcome to the Roku Community, Atwilley!
Thanks for letting us know about this issue that you had with the ARC since it is not working. There are several reasons why HDMI ARC might not be working on a Roku TV connected to a soundbar, including:
Loose connections
Check to make sure all HDMI cables are securely plugged into the TV and soundbar's HDMI ports. Also, check the power cables.
Incorrect settings
Ensure that the HDMI ARC setting is enabled on the TV and that the audio output settings are set to HDMI ARC.
HDMI cable
Use a high-speed HDMI cable and avoid long cables or adapters. HDMI cables for video and audio use different wires, so a cable that works for video might not work for audio.
We hope this helps. Please keep us posted if the problem still persists.
Best regards,
John