I am having the same issue. I have a MU6105 connected to a Nvidia Shield Tv 2017 since August working great with two firmware updates since then. I had the TV with no internet access to avoid this kind of problems. One weeks ago I had to connect the tv to the internet and updated the firmware to the lastest version. Since then the TV has been waking up shortly after I tuned off the TV and the Shield and the TV remote acting erratically when I was using the Shield through HDMI-CEC. Then I realized that the only thing that changed was the TV firmware.
I tuned off Anynet+ HDMI-CEC and the turning on problem was gone but I cant use the feature that I matter the most so it is not a solution whatsoever.
I am waiting form a firmware update to solve this problem.
Sorry for my english, it is not my strong suit.
@user34mui8y3BU, if it happened after a firmware update? Could you make a factory reset and check if that helps? I'm not willing to resign on using HDMI ARC myself, but doing a total factory reset and disconnecting the TV from internet is a viable solution.
I can categorically say that this isn't (only) due to connected devices as this has happened a few times with our ue32m5520 in the bedroom which has nothing connected and just used for netflix etc.
Here is the setup:
3 x UN65MU8000
1 x UN55MU8000
3 x random LG TVs
1 x Key Digital KD-HD8X8Lite HD Base T HDMI matrix
3 x Dishnet satellite receivers
2 x Apple TVs
Sonos Playbars on the Samsung TVs