None. So for OBS it seems that it's simply a performance issue.
But for the notifications, it seems weird that my fps falls to 30 or 60 and the same happens when sharing my screen with Discord.
Discord is also default version. Changing hardware acceleration between on/off does not change it.
I should mention, my fps in-game still says it several hundred, but it's like my entire screen refresh rate (or something similar) changes when I get a system notification.