I recently purchased a 77" S95F OLED TV (Model #: QN77S95FAFXZA).  When I purchased the TV I also got a Samsung soundbar (HW-S800D). The TV was in stock so I took it home and set it up, the soundbar had to be shipped.  The TV worked well when set up by itself.  However, once the soundbar arrived I set it up and plugged it into eARC (hdmi 3).  It connected and was working with qsymphony.  But after a while we noticed that the sound would stop working and the tv would start cutting back and forth from tv output to eARC.  power cycling things or manually turning off and on eARC seemed to resolve the issue but after turning off the tv for a while and coming back the sound would be messed up again, switching back and forth from qsymphony to tv output.  I tried several different settings and bought a new hdmi cable to try.  None of it worked, so I returned the soundbar.  I then bought a Sonos Arc Ultra soundbar.  

I came home set up the soundbar using the same hdmi 3 (eARC) port and everything worked great, except, when turning off the tv and going away for a bit and coming back and turning the tv on again the same problem occurs, the sound doesn't work through the soundbar and the tv sound flips back and forth from tv output for a few seconds to hdmi-earc for about a minute and then back.

I reached out to support and they verified my firmware on the tv was at the latest version (1042), walked me through a factory reset of the tv, power cycled everything. The power cycling always fixes the issue in the moment but then it comes back.

They said the only other option was to schedule a service, but if the technician doesn't find anything they will charge me for the visit. I have no faith that the technician will find anything since support was unable to help.  This is a brand new TV and Samsung's top of the line model.  Is there anything else to be done but return it?