I can bypass this problem by using the browser version of Discord. Might be useful for people with the same problem. The software itself is causing the issue for sure.
Only overlay I have enabled is the steam overlay which should not be causing the problem as the effect does not show up when that overlay is enabled and the VoIP's one isn't.
Whenever I play CS:GO / Trackmania 2 Stadium while using Teamspeak or Discord (only ones I can confirm) I get this microstutter effect that disrupts the fluency of 120+hz and is therefore very noticable on these frequencies. At first I thought my old Samsung 2233RZ (120hz) was dying, but after...