Download the Nvidia GeForce 398.8 hotfix driver as released by NVIDIA. It fixes Windowed G-Sync mode may stutter after upgrading to Windows 10 April 2018 Update... GeForce 398.86 hotfix driver download
Using Windows 10 64-bit (1803) with G-sync here + SLI. Not seeing any problems so i won't need the hotfix
You mean it seems that way with the stuttering bug? This makes no sense. G-Sync does the opposite, aids your frame rate.
Nvidia should consider allowing you download and install these hotfixes within geforce experience, this would be an awesome feature. Just a nice time saver, also because sometimes these hotfixes are pretty important and lots of people would miss out or not get them until the next full update. I assumed this would already be a thing, but upon checking I was surprised it isn't (unless I'm a nob and can't find it).