We've just received a ROKU Soundbar and have installed it using our trusty old Samsung LED TV from 2011. The HDMI ARC setup works fine except that it cuts off the audio out which we use to source some good wireless headphones. If we roll back to our old ROKU 3, all is good using that same port, the audio out is enabled. It also seems to kill the SPDIF optical output, that's dead as well until we disconnect the soundbar/ARC connection.
I've played with as many options as are available on this TV and with the HDMI ARC engaged with the ROKU Soundbar, the audio is disabled.
Wondering if anyone knows how you can work around this?