I also purchased the Q6f this past February. Worked fine for about 2 months, then chronic HDMI TV ARC connection issues with an LG soundbar. Optical cable worked fine. Replaced the circuit board on the TV and still issues. There was a firmware update in mid August that took care of the soundbar being turned off and flipping to TV speakers. Now instead there is NO AUDIO whatsoever. Requires a complete of the electronics (unplug everything for at least 10 minutes) and then reconnect everything. You're good a few days before it starts all over again. Samsung REFUSES to replace the defective tv or acknowledge the problem.
There supposedly is another firmware update for end of September that might fix it. I even purchased the other day a Samsung Dolby Atmos soundbar (K850) and have similar issues with a 4k pass thru and flickering picture, sound bar freezes, etc.
I WILL NEVER buy a Samsung product again. I have an LG OLED with -0- issues and it is connect to a Sony top of the line soundbar.
Wish us all luck - if I could I'd return it all to Best Buy. I even contacted the Office of the President for Samsung in NJ and the woman returned my email to them with the same offer that their foreign support offers. Absurd for a top of the line product.