Maybe it's a setting change to the HT system? But be sure to ask the maker of the HT system as well as calling Panasonic.
Have a new Pan TC-P50U50 plasma Tv and when it turns on, it mutes my home thearter sound. I have read the manual and see the "Speaker Control" on page 26 but its' not in the Viera link menu area on my TV as shown in the manual. Can anyone advise please.