2020 QLED T models (Q80T, Q90T, Q800T, Q900T) HDR game mode brightness / local dimming bug

[Rauttis]

I bought a Q80T a couple of days ago and have noticed a really annoying issue when using the tv with the combination of HDR and game mode.

I'm fairly certain this is a software bug in the TV since I can reproduce this issue with 100% accuracy, and it happens on the dot at the same moment every time. It's basically on a timer.

Basically when the game is displaying a HDR signal and game mode is enabled, exactly after 6 minutes the brightness of the TV suddenly drops by around 20 (50 -> 30). The value of brightness setting doesn't actually change however. Messing with the brightness setting does not restore the brightness to it's original state, but changing the local dimming setting from standard to low and then back to standard does. Switching game mode off and then back on also fixes the issue, but then it happens again EXACTLY after 6 minutes (I've timed this with a stopwatch).

Has anyone else experienced this issue? Or can someone maybe test this on their TV to see if you can reproduce it?

Exact repro steps on how I can reproduce this 100% of the time on the PS4 Pro:

1. Set brightness to max (50)
2. Set local dimming to standard (bug happens on high as well)
3. Enable game mode
4. Turn off game motion plus
5. Turn off intelligent mode and all the brightness related settings in eco settings, as these can influence the brightness level of the tv.
6. Launch a game that runs in HDR
7. Start your stopwatch
8. Do whatever you want in the game or you can also go back to PS4 menus, find a bright scene where you can notice a brightness drop easily
9. When the stopwatch hits 6 minutes, you should see the TVs brightness suddenly drop by a large amount. By eye the brightness drop seems about equal to dropping the brightness from 50 -> 30 by hand.
10. Go to picture settings and set local dimming to low (brightness does not change)
11. Set local dimming back to standard (brightness suddenly jumps to the original level. Brightness can be restored by switching input away and back as well, or by disabling and re-enabling game mode)
12. And again after EXACTLY 6 minutes the bug again repeats and the brightness drops down again

Some other notes: The PS4 has a screensaver that basically dims the screen if it is idle for a while. This is not the cause of this, this happens even when the console is in active use and the brightness can be restored temporarily by changing the local dimming setting like described above. I have not managed to reproduce this issue with game mode off, so it seems to be related to game mode.

Software version: 1304

[cod]

Lol, thought it had just struck, as I'd left game sitting on the lobby screen and just as I looked up it dimmed, but then I realised it was the Xbox doing it's "you haven't touched me for X minutes" thing. Phew!

[LCDeez]

I'm not sure I noticed it on COD, try FIFA if you own it. 

[jayh89]

I don’t notice it playing tsushima but I do with FIFA. It depends on the game (lighting etc). 

[cod]

I do not own FIFA. But there would be no reason for it not to happen with whatever game was on. I know I haven't noticed it with any other games that I've played.

[LCDeez]

Yep, something about the FIFA lighting that engages the dimming after 6 minutes or so. It also happens in other modes outside of game though (Filmmaker wink wink) 

[cod]

Like I said earlier, I haven't noticed it in any modes whether watching TV, films, or gaming.

[cod]

If it happens with FIFA, but not other games, then perhaps the issue is not the TV...

[LCDeez]

It’s definitely the TV, it has dimming issues for multiple modes for people (see 186 replies on this thread and some more on the US thread). Count yourself very lucky. A lot of people have the issue. 

[cod]

Well, but then my question would be why does it happen with FIFA but not other games? Or maybe it is happening with other games and just nobody has mentioned it.

[jayh89]

It does happen. It’s just way more noticeable with FIFA. I’ve saw it happen with the last of us 2 and Tsushima (but less obvious). Fifa is a very bright game (sunshine on grass etc) making it easy to see. It’s definitely there for most of us.