Are you perhaps trying to use BOTH TV speakers and Receiver speakers? TV speakers should be OFF here, entirely leaning on Receiver speakers. Some people try to use both together. Or some TVs offer an option to use TV speakers as "center" channel in a Receiver surround sound setup. If either are you, go into the settings in that Hi-Sense and set audio speakers to "receiver" or "external" or whatever it offers to tell it to only use Receiver speakers. Then give it a while and see if the problem comes back again.
How are you wired?
- AppleTV to Receiver to TV or
- AppleTV to TV to Receiver?
If not the first option, you might try a simple test with that setup and see if that might resolve your problem. There MIGHT be a timing issue in play such that when you turn on everything to watch something the TV and Receiver have not yet acknowledged each other when a sound is to be made. If so, perhaps TV only has its own speakers seeming to be available and thus they "take over" even when the Receiver is fully online/connected. This could be triggered as simply as having UI sounds on and thus a tone is to be played when turning everything on but Receiver has not quite connected with the rest... even more likely if your connection chain is the second type.
That shared, there have been bugs introduced in recent tvOS updates (note post #3 asking about LG). Have you tried
rebooting your remote?
I opt to NOT use the AppleTV remote but instead use a universal learning remote and it does not have that problem: receiver speakers are
always controlled when watching AppleTV stuff. My connection is AppleTV to Receiver to TV. I have some suspicions about your remote if you are not trying to simultaneously use TV speakers too. A reboot sometimes solves the problem for other bugs that involve the remote.
