Can not select TV speakers when connected via HDMI

I have a MBP fully updated connected to a Sony TV vis HDMI/miniport. Up until today this configuration was working fine. Suddenly, I can no longer select the HDMI speakers in my audio preferences. They are recognized and appear on the list but when I select them it has no effect. Before today, when the TV was connected the HDMI output would be automatically selected and I could not access the volume control from the menu bar, which is the way I prefer it.

I have restarted with no success in changing this behaviour. If I open/close the lid, the sound goes to the proper settings for about 2s but then the HDMI speakers are de-selected and the built-in speakers are highlighted. I can manually select the TV speakers but the setting has no effect.

However, I *am* getting audio output through the TV but can not control volume from the mac or any app. I slide the volume slider on the menu bar and the audio output does not change. The sound is also playing from the laptop speakers which is highly annoying.