Performance Degradation

Hi guys,

Ryzen 5 5600

Rtx 2070 SUPER

16gb 3000mhz ram

game on SSD

I have a major performance issue that is preventing me from enjoying this otherwise great game 

My problem is that the game's framerate drops significantly after playing for an hour or two

It changes from smooth 85-75 to 30-45 frames and really ruins the experience for me

The only solution I found is relaunching the game, or weirdly, changing graphics preset from ultra to some other

and then back to ultra, though this doesn't always work

I already checked my temperatures and it's not an overheating issue, also my gpu utilisation is at 97-99%

Im wondering if it's not some memory leak issue that's causing the performance to drop,

but i haven't monitored the memory usage so it's just a guess 

Any help would be greatly appreciated,

Thanks