Hi wondering if anyone has had a similar problem or has a solution?

I am getting significant stuttering after 1 lap or so at random times

FPS stay the same (locked at 100FPS), no vsync on a 144hz free-sync monitor (running @ 100hz)

pressing shift + N to turn sound off then on again makes everything go back to silky smooth. Going into audio and selecting primary audio driver has the same effect.

I have tried using Nvidia HD out via the monitor and Realtek audio via the mother board which makes no differnence.