I just changed from LG to said Samsung Q7F QLED TV GQ55Q7FNGT and got some problems with the auto motion plus. I already upgraded to the latest Firmware 1270.6 via USB, but that did not help either.
The Problem is that with any setting of auto motion plus enabled (auto or any manual setting) on certain scenes that flicker/flash (for example electricity flashes or similar), the picture gets badly distorted. Even pictures that are not even realy moving.
For anyone who has Netflix, you can find one such scene on "Dirk Gently" season 2, chapter 4 (house within a house) on 19:50 minutes for about 1 minute length. It's basicaly a white room with some wood and the scene has a flickering light. Motion plus now causes the whole background to get badly distorted, even though there is hardly any movement. Shapes showing up on some parts, that should not be there (on the white wall surfaces), while details disappearing on other parts (a crack on the door). Any setting of dejudder higher then 1, causes this problem.
My old 32" LG TV, which is also 100Hz, does not have this problem, even at highest motion smoothing settings. On the Samsung I basically got to set smoothing so low, that it totaly defies the point of buying a 100Hz TV.
Is my TV damaged and should be exchanged, or is this a software problem?