We have the newest Roku Ultra (4850X - Ultra, software version 14.0) with the top-of-line Bose soundbar and a 65-inch Sony TV. When we start watching TV in the morning there's no audio. We've tried many things, but the only way to get the audio working again is to turn off the power for everything and turning it back on again. After a cold restart, the audio works as it should for the rest of the day. We didn't have this problem with the old Roku Ultra that we just replaced.
We replaced all the HDMI cables, and that didn't help. Restarting only the Roku doesn't work. Restarting only the TV doesn't work. The Roku is plugged into the ARC HDMI input and the soundbar is plugged into the other high-capability port, as the TV says it should be. We tried swapping them, and that didn't work. We have also updated the firmware on all devices.
Only content from the Roku has this problem. Audio from the TV itself works when audio from the Roku does not.
We have no idea what to do to fix this problem, so help would be appreciated.