Hisense R6 Roku TV family ARC or eARC soundbar audio is not working

The checks in more detail

or to PCM or Stereo if there is no sound; look at HDMI and Digital Audio settings and the ARC option, and enable CEC, which Roku calls 1-Touch Play and System audio control in Settings, System, Control other devices (CEC). On the soundbar, select the ARC or HDMI ARC input. If the soundbar does not respond, power cycle both devices: turn them off, unplug for a minute, plug the soundbar in first and then the TV. A common fault is a cable plugged into an input and not the ARC port, or a soundbar that supports only eARC or only optical.

If the soundbar has an optical input, connect it to the TV's optical output as an alternative. Format mismatches cause silence, and a TV set to pass through Dolby Digital to a soundbar that handles only PCM gives no sound, so test Stereo. Remember that apps may output a format of their own, such as Dolby Atmos, which ARC without eARC cannot carry. If the volume buttons on the Roku remote do not control the soundbar, set up the remote's volume control in Settings, Remote and devices. Update the TV.

If sound works through the TV speakers and through optical but never through ARC on the right port with CEC on and the right cable, the port may be faulty, which Hisense can confirm. Check the Roku remote's own settings for volume control, since the remote can control the TV speakers or a soundbar by infrared, and set it for the device you use. If the volume keys change the TV level but the sound comes from the soundbar, the remote is not controlling the soundbar, and learning its code in the soundbar's menu or enabling CEC volume control fixes the habit of using two remotes.