Got an ONN 2.0 soundbar. Works well with tv through optical cable. But when I put a movie in the DVD player there is no sound. DVD player is hooked to tv with hdmi cable. The hulu and pandora app through dvd player have sound. Just not movies.
The soundbar owners manual may tell you what kind of digital audio it's compatible with.
Try selecting a different audio soundtrack type in the disc menu?
Try setting the DVD player to output in a different audio type in the DVD set up menu?