Playbar is installed for the TV with optical cable and TV´s own speakers are set off.
Volume is controlled thru the Sony remote control, set up with Sonos.
Playbar might change volume setting between the TV channels (also whatever streaming, Netflix etc. sources) or after restart.
Volume might be very loud or you can´t hear nothing...To solve such issues, I found only way to push remote control volume down (step by step to zero) and then again higher reaching the requested volume level.
This is really tiresome and I would be really thankful to find a way to solve the issues!