Hi. Got this monitor today and have the same issue, even on Intel UHD 750 integrated GPU. Do I have to replace this monitor or wait for firmware update ?

I too was having this issue and the fix I found was

1. Upgrade the display port cable to a VESA certified one

2. Remove the monitor drivers supplied by Dell and switch to using the default Generic PnP Monitor driver that appears by default when the Dell one is removed.

Being a VA display, it's still susceptible to flicker when scrolling through game menus and on loading screens. But the fast majority of gameplay is now flawless (tested on Call of Duty Cold War with a 6900xt and framerates constantly changing between 115 to 135 fps)

So you suggesting that Display Port cable provided by DELL is bad quality ?

Not necessarily bad, just not up to the standard needed for FreeSync to work well. 1440 x 3440 p at 144 hz is very close to the maximum total data rate of a display port cable (specifically it's 21.4 gbps and the maximum for the display port 1.4 standard is 25.92 gbps). Because of that, it has to be a perfectly to spec cable which the ones included with monitors generally aren't (not just Dell monitors, all monitors in general). A good way to tell if it's a good cable is if it's VESA certified display port 1.4. Other display port cables may indeed work without causing flicker but there's no way to tell for sure without trying it.

* Review the online S3422DWG User's Guide
* AMD FreeSync Pro is enabled in the AMD Control Panel and in the S3422DWG Menu- Game. The resolution is 3440x1440

* If connected via DP 1.4 to DP 1.4 =
- you need to test all Hz (144/100/60)
- you need to test each Hz on all four Response times (8ms/4ms/2ms/1ms)

* If connected via HDMI 2.0 to HDMI 2.0 =
- you need to test all Hz (100/60)
- you need to test each Hz on all four Response times (8ms/4ms/2ms/1ms)

Regards,

Paventhan M