It sounds like a setting is set wrong to me, sadly this is not a game I have played so I don't know its in game video settings
😕 But to try and help make sure in Nvidia control panel , under 3D settings , Adjust image settings with preview is set to Performance to start with always.
In game video settings if the game has this make sure this stuff is Off and if the game does not allow Off then set to Low... Supersampling (SSAA) OFF , Ambient OCCLUSION - OFF, FX AMOUNT OFF
With all origin games turn off origin in game and cloud storage both give issues in games at times
On PC power always set to high performance
Other things to give low FPS and stuttering on a pc is programs so use a clean boot please see this link for steps if you need it...
https://support.microsoft.com/en-ca/help/929135/how-to-perform-a-clean-boot-in-windows
Bios 602 and did a bios update doh
passed 8hr test on Karhu RamTest
Set to Manual OC
Dram Frequency 4266MHz
Dram voltage 1.45v
CPU VCCIO Voltage 1.25v
CPU System Agent Voltage 1.29v
Dram timing control 17-18-18-38
Mode1
Dram command rate set to 2N set dram current capability to 130%