"NVIDIA GPU only" making literally everything stutter

[Paro]

Every single time I enable "NVIDIA GPU only" from nvidia's control panel, everything starts stuttering. Like ANNOYING STUTTERING! Not just in games too, it's EVERYWHERE! I've seen it in task manager and whilst using fraps, the usage dips or spikes suddenly/the fps dips or spikes suddenly, which causes these ANNOYING stutters!

And the temps aren't even that high. GPU is around 51 Celsius degrees right now. (Having 3 tabs open including 1 yt vid, fraps, nvidia control panel, notepad, taskmanager)

In games I've tried using G-Sync, but it still dips and spikes! But when I enable Optimus, everything is smooth again (except when optimus decides to use the dGPU), so basically the problem is from the graphics card, right?

Please help. Thanks!

Laptop spec sheet: https://psref.lenovo.com/syspool/Sys/PDF/Legion/Lenovo_Legion_5_15ITH6H/Lenovo_Legion_5_15ITH6H_Spec.pdf

Mine is the 11400H with 3060 130W, 16GB's RAM and 1TB nvme

Edit: This is what I mean by dips and spikes. And that was only by scrolling up and down on a youtube 1080p vid..