I got myself a PUS7303 last year and just updated it to Oreo.
I use external speakers (connected via jack) and before the update I could control its volume simply with the remote.
After the update I can only control the volume on the speakers, even if I use an optical cable.
Downgrading is not an option unfortunately, the previous version was so buggy for me that it was almost unusable (TV randomly not turning on etc).
Please help me!
You have to go into the settings and change the headphone volume.