Volume Control greyed out on TV service.
I’ve been using homebridge webOS tv in my HomeKit setup for a while. Today I updated and changed config.json to use the new HomeKit TV service in iOS 12.2. So far so good, except that the TV volume control is greyed out on iOS. Previously, the volume as lightbulb service was working fine.

Any ideas?

More details - Apple TV 4K running tvOS 12.2 PB1
LG 55UH8500-UA running webOS 05.30.30