GSync and Halo Wars 2

I am having problem with gsync enabled and Halo Wars 2, game is so slow and sluggish and lots of freezes when gsync is enabled, navigation the menu and cut scenes. Game play seems good but still I am getting very bad performance.
By disabling gsync everything get better and run smoothly.
Any idea why this happens?
Thanks

GSync didn’t work at all for Windows 10 apps for a while, it’s supposed to now but not surprised it would have problems. They aren’t .exe files lots of software has issues interacting with them.

Also, has it been the entire time or possibly just since yesterday evening? I noticed after the update that messed up other stuff (crashes returning to main menu, black screen loading) that I couldn’t turn on Shadowplay without the game performance heavily suffering when it was perfectly fine prior. So maybe the update has something to do with it if so.

No even before the update was like this, after update no changes, still the same, I have to disable gsync