I have the identical problem...did Samsung ever send a solution? Looks like the thread just ended. My soundbar is <15 feet in the same room with a line of sight to the speakers, and it all keeps disconnecting
Would you mind tell how an HDMI cable can make the subwoofer and speakers disconnect?
It is possible the HDMI cable may be causing this symptom. Have you tested out another HDMI cable for the device?
I expericence the sub drop outs pretty much daily. Mostly happens in Spotify connect but it has happened while waytching TV or a movie. Samsung's "updates" have yet to fix this issue.