Hey HotS team,
Through some extensive troubleshooting on my own build (9900k, 1080ti, 32GB of 4000mhz Ram, hardwired, 15ms ping to US Central) I have been able to identify that any of the Nvidia 436 branch drivers cause 100+ fps drops in HotS (and SC2) and doing a DDU (display driver uninstaller) to 431.60 completely resolves the issue.
Windows 1903 is completely patched up-to-date, as is everything else on my system drivers wise - introducing the 436 branch driver results in wild FPS fluctuations, downgrading to the 431 branch resolves.
Can anybody else verify?