VG249Q Freesync/G-Sync Compatible input lag?

[ababa]

Hello, i got this screen monitor but i play mostly versus fighting games and not fps, this monitor has an average response time, i believe around 8.5 ms which is ok for me
But i have some problem with this monitor for fighting games, fighting games netcode differs from fps game netcode
Its explained here
https://arstechnica.com/gaming/2019/10/ ... k-netcode/
I play on SFV, i have no problem with my connection (up to 300 mbits) and build specs (2060 Super)
To sum up, when i play online, i got severe lags, especially against PS4 players (crossplateform game)
I also play with my friend from same country with also good connection/build, its better but it felt weird with missing inputs, dropped combos
So i have investigated further:
1/ When G-Sync is enabled on Nvidia driver panel and on my VG249Q own menu (Adaptive-Sync/Freesync), all other settings by default
2/ When G-Sync is enabled on Nvidia driver panel and on my VG249Q own menu (Adaptive-Sync/Freesync), Nvidia driver panel, V-Sync ON (forced), capped framerate at 60 fps
3/ G-Sync OFF, Adaptive-Sync/Freesync ON
4/ G-Sync OFF, Adaptive-Sync/Freesync OFF with DisplayPort
5/ HDMI instead of DisplayPort (G-Sync option doesnt show up)

I got the worst result with 1 when G-Sync and Freesync are both enabled
2/3 felt also weird
4 and 5 feels much less laggy
When i disabled both G-Sync and Freesync, game run smoother without much lag (rollback, missing image frames etc...)
Keep it mind in Street Fighter 5, G-Sync/Freesync are natively OFF, no matter of whatever settings, i always get 60 fps
The issues i ve got, why with some settings, i got terrible online experiences
My assumption is my monitor has bad freesync/g-sync implementation causing input lag, maybe i am wrong, its nocebo effect, i m really confused
Any thoughts?
Thanks

[moklys]

Which cable should I use?