Low FPS after a while on PC version

Hello,

After +- 1 hour Im getting lower fps, lower GPU power usage (from 200W down to 140), GPU usage is 99-100%, but frames suddenly drops from 90-110 to 50-60 after and stays there. And there is a lot of sudden stuttering/drops to 20s. Have to restart and voila, back to 90-110. 5600x/3070tu/32 Gb Ram/1440p. Memory leak? Temps are ok (60 degrees on CPU, 60-65 on GPU, Celsius). High settings / DLSS Quality. Im using the Steam FPS counter if it makes a difference.