Samsung TV sound low to soundbar

. my optical out is fixed , the only time I do get a higher volume is when there is a commercial on or another channel on the TV while watching a movie that’s broadcast-ed or streamed louder. I have tried all the sound settings and the only thing that is for some reason when set to sound voice guide [on] directs this voice through the optical out port to my sound bar and is very loud and that is what I wish would stay there during a movie watching however it only works when-the TV’s voice talking out the words for example volume up ,volume down, or mute. ?