I too had nothing but problems between the Q90R soundbar and an old Samsung F-8000 TV (but still a good picture). I had continueous bouncing betwwen ARC and D.IN on the soundbar. And I too having the TV loosing the ARC connection to the Soundbar. I gave up with using ARC and since you can not directly choose the soundbar input (have to cycles through the inputs to change) and is pretty much useless with a Harmony remote. So I bought a HDMI switch and all my devices (DirecTV, DVD, ROKU, etc) go into its input and the output to the soundbar input port-1. Then the soundbar output goes to the TV HDMI-1 port. I also had to turn off the TV's Anynet+ (HDMI-CEC) else for some reason it caused the soundbar to switch back to D.IN (from HDMI-1) at times even though it was not hooked to the TV's ARC port. Crazy! And since the switch allowed the Harmony hub select which input port of switch, it was pretty much solid. So far (1 week now) it's been pretty solid without issues.
I can't believe Samsung has not released any firmware updates since last July with so many problems by so many people!
I have the same problem with my computer.
the screen is keep losing connection off the hdmi input and inly when i restart the computer or reconnecting the hsmi cable its ok.
I had another samsung tv before that and i had no problems. this onr having a problem keeping the connection of the sound.
This is still a problem for a ton of people. Samsung doing nothing to fix the issue. Support at Samsung acts like it is a new problem and unique to the soundbar or the TV. It is a connection problem between the two of them. Ridiculous that Samsung has not fixed these issues after 6+ months of posts regarding this issue.