[Regression Bug] Samsung 2020 QLED TVs - GameMode is breaking the refreshrate while using Samsung DEX

[RouDeR]

Steps to reproduce:
1. Have a Samsung 2020 TV (Mine is Q800T) 
2. Have a Samsung DEX supported device like Galaxy S8,9,10,20  or Note 8,9,10

3. Connect the phone to the TV  > at this point everything will be OK (no issues with the picture)
4. Enable Game Mode > You will see a HUGE CONSTANT tearing and glitches at the bottom part of the screen, they are hugely desynced (bottom part of the screen have like 1 second delay of refreshing the image)

Additional Information:
Software version : 1115
TV: Q800T 75 inch (europe)
I also have Samsung KS7502 (2016 model I think) and I have no issues with Game Mode and Samsung Dex there !!!
Next week I`ll be getting Samsung The Frame 2020 and will report if this issue happens there as well.
Tested with 2 phones: Galaxy S8 and Galaxy Note 9

Video showcase:
https://www.youtube.com/watch?v=lnjt0SOxu2s&feature=youtu.be

[smp1]

This glitch randomly appear in Game Mode on my 2018 UE40NU7100 TV. The tearing can appear with any HDMI device in any part of the screen, not just the bottom part.

[RouDeR]

@smp1  I`m sure that you are talking about regular tearing, it is not the same bug,
This is what I`m talking about:
https://www.youtube.com/watch?v=lnjt0SOxu2s&feature=youtu.be

[smp1]

It's the same issue that I see in Game Mode.

In my case that horizontal "line" is sometimes slowly moving and it can go away after a few seconds.  Sometimes it remain static until the HDMI video mode is changed.

[RouDeR]

Well for me it is always when using Samsung DeX with Game Mode there is no workaround for it and i`m also using the original Samsung DeX Station.
Like I said I have no such issues on my 2016 Samsung TV with DeX.

[RouDeR]

I just bought Samsung the Frame 2020 55 inch,
It has the EXACT SAME ISSUE, the tearing is atrocious when using Game Mode with DeX

[RouDeR]

UP

[RouDeR]

Found workaround for this bug,

To resolve it you need to enable Game Motion Plus and set the options there to 0 (if any of them is set to 1 or more the bug still happens)

Extremely annoying workaround as it add input lag..

[smp79]

This should now be fixed with the latest firmware (for 2019 and 2020 models).

[RouDeR]

1301.5 will be available in Europe sometimes next month probably.