,,Weird'' Stutters.

Hello there,
Recently I've started getting ,,weird'' stutters while in-game. Precisely, while I am playing the normal game or ranked, sometimes after playing for a while, I get weird stutters from 4 to 6 every 3-5 seconds, one stutter is lasting from 1 to 2 seconds max. It's really annoying since this all started at the end of Season 10. I've read somewhere that it might be the PSU problem and I should change the power plan to Highest Performance/Ultimate Performance, but that didn't work. Sometimes I am not even able to properly focus on the game because of these ,,weird'' stutters. Also every stutter, my fps is dropping drastically to below 60 from a constant 144. I bought pc 6 months ago.

Specifications: 

CPU: Processor Intel(R) Core(TM) i5-10400F CPU @ 2.90GHz, 2904 Mhz, 6 Core(s), 12 Logical Processor(s)

OS: Name Microsoft Windows 11 Home

Motherboard: BaseBoard Product B560M DS3H, BaseBoard Version x.x
Power Supply: SilentiumPC Vero L3 600W 80 Plus Bronze

GPU: Palit GeForce GTX 1660 Ti StormX 6GB GDDR6.

To be honest, I personally think it might be the PSU problem because it is pretty cheap, but I hope it is not.

Thanks for helping. Have a nice day/night!

P.S. I suck at English.