Changes in CEC behavior?

Running tvOS 11.1 beta 1 the Apple TV 4K seems to 'lose' CEC authorization after a certain period of time in sleep mode. Normally (read: 1+ year) the device will flawlessly turn on my Sony Bravia XBR49800D, switch to its input, control the volume, sleep, and subsequently reawaken all devices, etc. Now it will only do so after a full reboot and then only until it puts all devices to sleep where the CEC functionality is inexplicably lost. I'm fairly certain that this is a result of the beta software and not a problem with the TV or HDMI cable.